Auto merge of #111345 - jyn514:cfg-release-caching, r=cjgillot,est31

Only depend on CFG_VERSION in rustc_interface

This avoids having to rebuild the whole compiler on each commit when `omit-git-hash = false`.

cc https://github.com/rust-lang/rust/issues/76720 - this won't fix it, and I'm not suggesting we turn this on by default, but it will make it less painful for people who do have `omit-git-hash` on as a workaround.

compiler/rustc_interface/src/util.rs

@@ -104,6 +104,7 @@ pub fn create_session(
         lint_caps,
         file_loader,
         target_override,
+        rustc_version_str().unwrap_or("unknown"),
     );
 
     codegen_backend.init(&sess);