Remove vcpkg

[jeaye]

Reasoning

vcpkg does not meet its portability promises. Some deps fail to build with it. It can't work with Nix. It complicates the CMake toolchain. It doesn't properly handle x86_64/arm64 triplet separations.

Steps

I went through our vcpkg.json to see what we can do about each of the deps. Looks like only one of them needs compilation. The majority can be global distro packages. A few we'll need to bring in as submodules (like compiler+runtime/third-party/bpptree and others).

• [x] bdwgc
  • submodule with CMake build system
• [x] boost-algorithm: distro package (boost)
• [x] boost-filesystem: distro package (boost)
• [x] boost-smart-ptr: distro package (boost)
• [x] boost-variant: distro package (boost)
• [x] boost-preprocessor: distro package (boost)
• [x] fmt: distro package (fmt)
• [x] readline: distro package (readline)
• [x] cli11: header-only; submodule https://github.com/CLIUtils/CLI11 into compiler+runtime/third-party/cli11
• [x] immer: header-only; submodule https://github.com/arximboldi/immer into compiler+runtime/third-party/immer
• [x] magic-enum: header-only; submodule https://github.com/Neargye/magic_enum into compiler+runtime/third-party/magic_enum
• [x] libassert: skip this, we're not using it right now
• [x] libzippp:
  • needs compilation
  • submodule https://github.com/ctabin/libzippp into compiler+runtime/third-party/libzippp
  • uses cmake, so we should be able to build it as an external project