revert invalid change

Author: boomanaiden154

.github/workflows/pr-code-format.yml

@@ -38,7 +38,7 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           repository: ${{ github.repository }}
-          ref: ${{ github.ref }}
+          ref: ${{ github.base_ref }}
           sparse-checkout: |
             llvm/utils/git/requirements_formatting.txt
             llvm/utils/git/code-format-helper.py