Upstream is now vendoring the Cargo.lock file for reproducible app builds, so we
can now remove the patching workaround. However, they're missing a git tag, so
we have to do some work to find the right git commit.
Changes the default fetcher in the Rust Platform to be the newer
`fetchCargoTarball`, and changes every application using the current default to
instead opt out.
This commit does not change any hashes or cause any rebuilds. Once integrated,
we will start deleting the opt-outs and recomputing hashes.
See #79975 for details.
