Rollup merge of #138330 - nnethercote:rm-lints-rust-sections, r=jieyouxu

Remove unnecessary `[lints.rust]` sections.

`bootstrap` and `llvm_enzyme` are now both in the extra `check-cfg` list in bootstrap, so they doesn't need to be handled explicitly in `Cargo.toml` files.

r? ```@jieyouxu```

Author: Kobzol