undo unnecessary changes

Author: ZuseZ4

compiler/rustc_llvm/Cargo.toml

@@ -14,6 +14,3 @@ libc = "0.2.73"
 # pinned `cc` in `rustc_codegen_ssa` if you update `cc` here.
 cc = "=1.2.7"
 # tidy-alphabetical-end
-
-[lints.rust]
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(llvm_enzyme)'] }