Cleanup deps

[kziemianek]

Some dependencies are not needed anymore, some can be trated as dev dependencies only, for example if they are used in tests only.

This PR tries to tidy Cargo.toml files a little bit which might eventually lead to:

• better developer experience
• shorten build times

I've applied rustc lint rule to modules one by one to see what deps are not used.

This rule cannot be toggled on because it might produce false-positives depending on specified build features.

[Kailai-Wang]

Thank you! I'm wondering if there's any tool for it? Not necessarily integrated in CI but we can use it locally at least

[kziemianek]

Thank you! I'm wondering if there's any tool for it? Not necessarily integrated in CI but we can use it locally at least

Yes 🙃 previously I tried with rustc lint rule but I found out machete to be really acurate. I had also exerimented with udeps but without a success.

[Kailai-Wang]

Looks good from my side 👍