Fix label-sync to specify repo and add checkout step

Author: coisa

.github/workflows/label-sync.yml

@@ -21,6 +21,9 @@ jobs:
     if: inputs.copy_issue_labels == true || github.event_name != 'workflow_call'
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
       - name: Extract issue number from PR
         id: extract-issue
         env:
@@ -38,12 +41,13 @@ jobs:
       - name: Copy labels from issue to PR
         if: steps.extract-issue.outputs.issue_number != ''
         run: |
-          LABELS=$(gh issue view "$ISSUE_NUM" --json labels --jq '.labels[].name')
+          LABELS=$(gh issue view "$ISSUE_NUM" --repo "$REPO" --json labels --jq '.labels[].name')
 
           for label in $LABELS; do
-            gh pr edit "$PR_NUM" --add-label "$label" 2>/dev/null || true
+            gh pr edit "$PR_NUM" --repo "$REPO" --add-label "$label" 2>/dev/null || true
           done
         env:
           ISSUE_NUM: ${{ steps.extract-issue.outputs.issue_number }}
           PR_NUM: ${{ github.event.pull_request.number }}
+          REPO: ${{ github.repository }}
           GH_TOKEN: ${{ github.token }}