style: remove legacy extern crate declarations

[minxuanz]

After rust edition 2018, use statements can import procedural macro
https://doc.rust-lang.org/book/ch20-05-macros.html

[CLAassistant]

All committers have signed the CLA.

[Oyami-Srk]

LGTM, Thanks for your contribution! 🚀

[Oyami-Srk]

Oh, the failure is because we use the pull_request trigger, so we lack the permission for a forked repo.