Fix check-cfg-related and rust-lld-related CI failures

[ryoqun]

Fix master ci, which is broken due 2 problems:

• the new check-cfg: https://blog.rust-lang.org/2024/05/06/check-cfg.html
• the default linker change: https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html

[ryoqun]

@github-actions CI / careful (pull_request) Failing after 42s

well, well, well. celebrate rapid development progress of rust nightly? seems https://blog.rust-lang.org/2024/05/17/enabling-rust-lld-on-linux.html is the culprit for the careful failure...

[ryoqun]

@taiki-e Following from https://github.com/crossbeam-rs/crossbeam/pull/1109#issuecomment-2119119507, it seems ci is green again in another approach. could you review this?