CI: Fix label Checker (#32770)

Fix label Checker

.github/workflows/pr-automation.yml

@@ -20,6 +20,11 @@ jobs:
       matrix: ${{ steps.checkAll.outputs.matrix }}
     steps:
 
+      # Checkout the code in the current branch in case the workflow is called because of a branch push event
+      - name: Checkout the head commit of the branch
+        if: inputs.pr == 0
+        uses: actions/checkout@v4
+
       # Checks for ok-to-test label presence in PR
       - name: Check label
         run: |