chromadb: add build-chromadb.yml for riscv64 wheels

[luhenry]

• Package: chromadb
• Version: 1.5.9
• Source: https://github.com/chroma-core/chroma
• Docs: https://docs.trychroma.com

A thin Python layer over a large Rust workspace, compiled by maturin into the chromadb_rust_bindings extension. Upstream publishes no riscv64 wheel.

Mirrors upstream's _build_release_pypi.yml and the test-rust-bindings job of _python-tests.yml.

Differs from upstream

• musllinux dropped — rustup ships no riscv64 musl toolchain.
• protoc comes from Rocky's CRB repo rather than a release tarball.
• Release debug info off — maturin strips it from the wheel anyway.

Matrix: one cp39-abi3 wheel, built once and tested on cp312/cp313/cp314, because pyo3 is pinned to abi3-py39 workspace-wide. Upstream ships no free-threaded wheel.

Testing

• grpcio, numpy and pandas resolve from our registry; PyPI's newest releases have no riscv64 wheel.
• chroma-hnswlib builds from sdist with HNSWLIB_NO_NATIVE, matching its own release workflow.
• Lint and codegen tooling from requirements_dev.txt left out; the suite never loads it.

License: Wheel statically links the Rust crate graph and carries upstream's Apache-2.0 LICENSE plus maturin's SBOM, as upstream's wheels do.

Patches

• 0001-test-create-an-event-loop-when-there-is-no-current-on.patch — To upstream. Three async_client tests fail on CPython 3.14, where asyncio.get_event_loop() no longer creates a loop. Reproduces off riscv64.

649 passed, 156 skipped, 1 xfailed on each of cp312, cp313 and cp314.