Allow PR checkout for backport action (#1085)

Author: nzbr

.github/workflows/on_label.yml

@@ -32,6 +32,8 @@ jobs:
 
       - name: Checkout
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
+        with:
+          allow-unsafe-pr-checkout: true
 
       - name: Create backport PR
         id: backport