Rollup merge of #121228 - onur-ozkan:fix-clippy-stamp-bug, r=albertlarsan68

create stamp file for clippy

Due to missing stamp file, we were downloading (and applying nix patches if enabled) continuously every time `Config::download_clippy` was called. This change fixes that by creating stamp file at the end of the function.

Fixes #119442

Author: matthiaskrgr