fix: add missing checkout step in backfill manifests workflow

Signed-off-by: Adilhusain Shaikh <[email protected]>

Author: adilhusain-s

.github/workflows/backfill-manifests.yml

@@ -22,6 +22,9 @@ jobs:
     outputs:
       matrix: ${{ steps.set-matrix.outputs.matrix }}
     steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
       - name: Fetch release tags
         id: set-matrix
         env: