[ci] Add missing permissions for labeling core team PRs

Missed this one earlier.

Author: poteto

.github/workflows/shared_label_core_team_prs.yml

@@ -20,6 +20,11 @@ jobs:
     if: ${{ needs.check_maintainer.outputs.is_core_team == 'true' }}
     runs-on: ubuntu-latest
     needs: check_maintainer
+    permissions:
+      # Used by check_maintainer
+      contents: read
+      # Used to add labels
+      issues: write
     steps:
       - name: Label PR as React Core Team
         uses: actions/github-script@v7