Rust: Vendor 3rdparty dependencies.

We've been observing some performance issues using crate_universe on CI.
Therefore, we're moving to vendor the auto-generated BUILD files
in our repository. This should provide a nice speed boost, while
getting rid of the complexity of the "rust cache" job we've been using
when we had a lot of git dependencies.

This PR includes a vendor script, and I'll put up a CI job internally
that runs that vendor script on Cargo.toml and Cargo.lock changes, to check
that the vendored files are in sync.

rust/extractor/Cargo.toml

@@ -3,6 +3,7 @@ name = "codeql-rust"
 version = "0.1.0"
 edition = "2021"
 
+# When updating these dependencies, run `misc/bazel/3rdparty/update_cargo_deps.sh`
 [dependencies]
 anyhow = "1.0.86"
 clap = { version = "4.5.16", features = ["derive"] }