chore: some installed deps are not needed

[huitseeker]

Some dependencies specified in Cargo.toml are not needed.

Check the unused dependencies sanity check workflow for details.

This issue was raised by the workflow at https://github.com/lurk-lab/ci-workflows/tree/main/.github/workflows/unused-deps.yml.

Note
If this is a false positive, please refer to the cargo-udeps docs on how to ignore the dependencies.