Fix label cleanup (#754)

Signed-off-by: Simon Davies <simongdavies@users.noreply.github.com>

Author: simongdavies

.github/workflows/ReleaseBlockerLabelCleanUp.yml

@@ -12,6 +12,8 @@ jobs:
   remove-release-blocker:
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
       - name: Remove release-blocker label from closed issue
         run: |
           ISSUE_NUMBER=${{ github.event.issue.number }}