delta-kernel-rust-sharing-wrapper: add build-delta-kernel-rust-sharing-wrapper.yml for riscv64 wheels

[luhenry]

• Package: delta-kernel-rust-sharing-wrapper
• Version: 0.3.3
• Source: https://github.com/delta-io/delta-sharing
• Docs: https://github.com/delta-io/delta-sharing

A PyO3 wrapper around delta-kernel-rs, giving the delta-sharing Python connector Arrow-backed Delta Lake table scans and change-data-feed reads. Upstream publishes no riscv64 wheel.

Mirrors upstream's build-kernel-wheels.yml build job.

Differs from upstream

• No git tags; pinned to the release commit, verified byte-identical to the 0.3.3 sdist.
• Rust toolchain installed in-container rather than on the runner.
• LICENSE.txt staged beside pyproject.toml so it reaches the wheel.
• musllinux dropped - rustup ships no riscv64 musl toolchain.

Matrix: cp312-abi3 (pyo3 abi3-py310, built on cp312 and re-tested on cp313/cp314) plus cp314t.

Testing

• No test suite ships with this crate; smoke-tests the URL-parsing and object-store construction path every caller goes through first.

License: Upstream's wheel ships no licence text; the build adds the repo's Apache-2.0 LICENSE.txt.

Built on cp312.