Set permissions to the actions

This commit update the actions  "Auto Assign Author", "Auto Label PRs",
and  "Auto Request Review"

Signed-off-by: Daniel Jiang <daniel.jiang@broadcom.com>

.github/workflows/auto_label_prs.yml

@@ -8,6 +8,10 @@ on:
   pull_request_target:
     types: [opened, reopened, synchronize, ready_for_review]
 
+permissions:
+  contents: read
+  pull-requests: write
+
 jobs:
   # Automatically labels PRs based on file globs in the change.
   triage:
@@ -15,5 +19,4 @@ jobs:
     steps:
       - uses: actions/labeler@v5
         with:
-          repo-token: "${{ secrets.GITHUB_TOKEN }}"
           configuration-path: .github/labeler.yml