Switch to #[proc_macro]

[EmbersArc]

From the proc-macro-hack readme:

Note: As of Rust 1.45 this crate is superseded by native support for #[proc_macro] in expression position. Only consider using this crate if you care about supporting compilers between 1.31 and 1.45.

I don't know if this is a drop-in replacement but it may be worth considering to native proc macros. proc-macro-hack leads to some unexpected things like false positives in rust-analyzer: rust-lang/rust-analyzer#6835