ci: add minimum GitHub token permissions for workflows

Signed-off-by: Ashish Kurmi <akurmi@stepsecurity.io>

.github/workflows/lock.yaml

@@ -7,8 +7,14 @@ on:
   schedule:
     - cron: '0 0 * * *'
 
+permissions:
+  contents: read
+
 jobs:
   lock:
+    permissions:
+      issues: write  # for dessant/lock-threads to lock issues
+      pull-requests: write  # for dessant/lock-threads to lock PRs
     runs-on: ubuntu-latest
     steps:
       - uses: dessant/lock-threads@v3

.github/workflows/tests.yaml

@@ -16,6 +16,9 @@ on:
       - 'docs/**'
       - '*.md'
       - '*.rst'
+permissions:
+  contents: read
+
 jobs:
   tests:
     name: ${{ matrix.name }}