(maint) - Remove redundant conditional checkout

.github/workflows/mend.yml

@@ -12,19 +12,7 @@ jobs:
   mend:
     runs-on: ubuntu-latest
     steps:
-      # If we are on a PR, checkout the PR head sha, else checkout the default branch
-      - name: "Set the checkout ref"
-        id: set_ref
-        run: |
-          if [[ "${{ github.event_name }}" == "pull_request_target" ]]; then
-            echo "ref=${{ github.event.pull_request.head.sha }}" >> $GITHUB_OUTPUT
-          else
-            echo "ref=${{ github.ref }}" >> $GITHUB_OUTPUT
-          fi
-
       - uses: actions/checkout@v4
-        with:
-          ref: ${{ steps.set_ref.outputs.ref }}
 
       - uses: "actions/setup-java@v4"
         with: