chore: add pull-requests write permission for add-pr-comment action

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: AlinsRan

.github/workflows/conformance-test.yml

@@ -37,6 +37,7 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       packages: read
+      pull-requests: write
     steps:
       - name: Checkout
         uses: actions/checkout@v4