Add PR permissions

Author: sarahchen6

.github/workflows/update-jmxfetch-submodule.yaml

@@ -10,6 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     permissions:
       contents: write
+      pull-requests: write
     steps:
       - name: Checkout repository
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # 4.2.2