ci: reset author/timestamp on rust overlay update

.github/workflows/update-rust-overlay.yml

@@ -23,7 +23,7 @@ jobs:
           git config user.name "Github Action"
           git config user.email "[email protected]"
           git add flake.lock
-          git commit --amend -m "build: update rust-overlay"
+          git commit --amend --reset-author -m "build: update rust-overlay"
           git rebase origin/main
       - name: Push changes
         if: steps.commit.outcome == 'success'