allow pr_target test runs

Author: l

.github/workflows/validate-pr-metadata.yml

@@ -24,7 +24,10 @@ jobs:
     if: ${{ github.event.label.name == 'Needs Review' }}
     steps:
       - name: checkout base branch
-        uses: actions/checkout@v5
+        uses: actions/checkout@v7
+        allow-unsafe-pr-checkout: true
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
       - name: Get changed files
         id: changed-files
         uses: tj-actions/changed-files@v47.0.5