Fix flags Json serialization

[rtbo]

These flags always appear empty in dub describe

[github-actions[bot]]

✅ PR OK, no changes in deprecations or warnings

Total deprecations: 15

Total warnings: 0

Build statistics:

 statistics (-before, +after)
-executable size=5276640 bin/dub
+executable size=5280736 bin/dub
 rough build time=76s

Full build output

``` DUB version 1.31.1, built on May 12 2023 LDC - the LLVM D compiler (1.32.2): based on DMD v2.102.2 and LLVM 15.0.7 built with LDC - the LLVM D compiler (1.32.2) Default target: x86_64-unknown-linux-gnu Host CPU: skylake-avx512 http://dlang.org - http://wiki.dlang.org/LDC Registered Targets: aarch64 - AArch64 (little endian) aarch64_32 - AArch64 (little endian ILP32) aarch64_be - AArch64 (big endian) amdgcn - AMD GCN GPUs arm - ARM arm64 - ARM64 (little endian) arm64_32 - ARM64 (little endian ILP32) armeb - ARM (big endian) avr - Atmel AVR Microcontroller bpf - BPF (host endian) bpfeb - BPF (big endian) bpfel - BPF (little endian) hexagon - Hexagon lanai - Lanai mips - MIPS (32-bit big endian) mips64 - MIPS (64-bit big endian) mips64el - MIPS (64-bit little endian) mipsel - MIPS (32-bit little endian) msp430 - MSP430 [experimental] nvptx - NVIDIA PTX 32-bit nvptx64 - NVIDIA PTX 64-bit ppc32 - PowerPC 32 ppc32le - PowerPC 32 LE ppc64 - PowerPC 64 ppc64le - PowerPC 64 LE r600 - AMD GPUs HD2XXX-HD6XXX riscv32 - 32-bit RISC-V riscv64 - 64-bit RISC-V sparc - Sparc sparcel - Sparc LE sparcv9 - Sparc V9 systemz - SystemZ thumb - Thumb thumbeb - Thumb (big endian) ve - VE wasm32 - WebAssembly 32-bit wasm64 - WebAssembly 64-bit x86 - 32-bit X86: Pentium-Pro and above x86-64 - 64-bit X86: EM64T and AMD64 xcore - XCore Upgrading project in /home/runner/work/dub/dub/ Starting Performing "release" build using /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/ldc2 for x86_64. Building dub 1.33.0-beta.1+commit.5.ga8f27eb0: building configuration [application] source/dub/internal/dyaml/node.d(2513,9): Deprecation: scope variable `this` assigned to non-scope parameter `_param_0` calling `match` source/dub/dependency.d(917,18): Deprecation: scope variable `this` assigned to non-scope parameter `oth` calling `opEquals` source/dub/dependency.d(920,30): Deprecation: scope variable `this` assigned to non-scope parameter `a` calling `doCmp` source/dub/dependency.d(921,27): Deprecation: scope variable `this` assigned to non-scope parameter `b` calling `doCmp` source/dub/dependency.d(939,26): Deprecation: scope variable `this` assigned to non-scope parameter `oth` calling `opEquals` source/dub/internal/configy/Exceptions.d(130,34): Deprecation: reference to local variable `buffer` assigned to non-scope anonymous parameter source/dub/internal/configy/Exceptions.d(134,34): Deprecation: reference to local variable `buffer` assigned to non-scope anonymous parameter source/dub/internal/configy/Exceptions.d(248,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(250,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(283,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(286,27): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(323,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(325,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(332,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` source/dub/internal/configy/Exceptions.d(335,31): Deprecation: `@safe` function `formatMessage` calling `formattedWrite` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/write.d(537,34): which calls `std.format.spec.FormatSpec!char.FormatSpec.writeUpToNextSpec!(void delegate(in char[]) @safe).writeUpToNextSpec` /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): which would be `@system` because of: /opt/hostedtoolcache/dc/ldc2-1.32.2/x64/ldc2-1.32.2-linux-x86_64/bin/../import/std/format/spec.d(258,33): scope variable `this` assigned to non-scope parameter `e` calling `put` Linking dub STAT:statistics (-before, +after) STAT:executable size=5280736 bin/dub STAT:rough build time=76s ```

[WebFreak001]

CI failures unrelated / pre-existing