Rollup merge of #125990 - tbu-:pr_unsafe_env_lint_name, r=ehuss

Rename `deprecated_safe` lint to `deprecated_safe_2024`

Create a lint group `deprecated_safe` that includes `deprecated_safe_2024`.

Addresses https://github.com/rust-lang/rust/issues/124866#issuecomment-2142814375.

r? `@ehuss`

compiler/rustc_lint/src/lib.rs

@@ -322,6 +322,8 @@ fn register_builtins(store: &mut LintStore) {
         REFINING_IMPL_TRAIT_INTERNAL
     );
 
+    add_lint_group!("deprecated_safe", DEPRECATED_SAFE_2024);
+
     // Register renamed and removed lints.
     store.register_renamed("single_use_lifetime", "single_use_lifetimes");
     store.register_renamed("elided_lifetime_in_path", "elided_lifetimes_in_paths");