bug: python.yml does not run when the root .cargo/config.toml changes

[LuciferYang]

python.yml's pull_request paths: filter has Cargo.* and python/**, but no entry for the repository-root .cargo/config.toml. That file reaches the wheel builds, so a change to it can alter what the Python extension compiles with and trigger no Python job.

The reason it reaches them is that python/.cargo/config.toml duplicates rather than replaces the root file. Cargo merges configuration from the directory hierarchy, so a python-rooted build reads both, and any key the sibling does not set comes from the root. The x86 rustflags line is set in both, which is why this has not bitten yet, but the root file also carries [profile.release], release-with-debug and release-no-lto, none of which the sibling defines.

It went unnoticed on #8754 because that pull request changed both files together, so python/** matched and the Python jobs ran. A root-only edit would not.

Same class as #8867, which adds the two missing entries to rust.yml, but a different workflow, so it wants its own one-line change: add .cargo/config.toml to python.yml's filter.

[LuciferYang]

java.yml has the same shape, and worth folding into whichever change fixes this one.

Its filter is java/**, rust/** and .github/workflows/java.yml. There is no .cargo/ under java/ or java/lance-jni/, so its rust-clippy-fmt job, which runs cargo clippy --all-targets --locked -- -D warnings, picks up the repository-root .cargo/config.toml and the root clippy.toml by the ancestor walk, with nothing in its filter naming either.

So a root-only edit to either file changes what the Java JNI crate compiles with, or what its clippy job enforces, and triggers no Java job. #8754 masked it the same way it masked the Python case: it also touched python/.cargo/config.toml, which fired python.yml.

Two entries would close both, .cargo/config.toml in python.yml and both files in java.yml.

[wjones127]

I agree this is worth fixing.