fix: use kebab-case as underscores are not allowed in edition 2024

[weihanglo]

The change is compatible. Just prepare for edition 2024 in advance.

See also:

• https://github.com/rust-lang/cargo/issues/13629
• https://github.com/rust-lang/cargo/pull/13783
• https://github.com/rust-lang/cargo/pull/13798
• https://github.com/rust-lang/cargo/pull/13804

[shepmaster]

Thanks!