use `--all-features`

[mccalluc]

• will fix #1525

WIP:

• test runs now produce vega graphs -- If we don't want these as a part of every run, maybe use skip instead of feature gating?
• Still need to handle tasks.json
• Makevars* and rust_build.sh parameterize --features ... Maybe we still want the flexibility there?

[mccalluc]

I'm going to say this much is ready for review. There are more references to --features but I'll address that in a separate PR, to keep this much from getting muddled.

R/opendp/src/Makevars.in:
  30:       @BEFORE_CARGO_BUILD@ cargo build --manifest-path rust/Cargo.toml --color always --release --jobs 2 --offline --features @RUST_FEATURES@; \

R/opendp/src/Makevars.win.in:
  34:       @BEFORE_CARGO_BUILD@ cargo build --manifest-path rust/Cargo.toml --target=$(TARGET) --color always --release --jobs 2 --offline --features @RUST_FEATURES@; \

tools/rust_build.sh:
  86:   CMD+=(--manifest-path=rust/Cargo.toml --features="$FEATURES")

• See #1532

[mccalluc]

CI failure in r-tests: Also saw the same problem on main and filed an issue:

• 1531

The last commit here only touched tasks.json, so the r-tests problem is non-deterministic, even though it seems to be related to the build. Exciting.

Rerunning the failing test.