Merge pull request #27 from conda-incubator/fix/conda-global-conda-ex…

…ec-docs

Clarify conda-exec handoff in docs

CI: bust rust-cache when Cargo.lock changes

Rust E0460 on macOS (stale objc2/ctrlc rmeta) came from Swatinem/rust-cache
restoring a pre-lockfile-regeneration target dir. Include hashFiles of
Cargo.lock in cache keys so dependency graph changes get a fresh cache.

fix(ci): pass Cargo.toml to maturin instead of pyproject.toml

maturin's -m/--manifest-path flag expects a Cargo.toml, not a
pyproject.toml. This caused all trampoline build jobs to fail.