ci(consistency): declare contents: read

The Consistency workflow runs lint / format / changelog-verify checks on
pull_request and push to main and doesn't touch the API. Mirror the
top-level permissions style already used in prepare-auto-release-branch.yml
and pin the default GITHUB_TOKEN to read-only.

Signed-off-by: Arpit Jain <arpitjain099@gmail.com>

Author: arpitjain099

.github/workflows/consistency.yml

@@ -10,6 +10,9 @@ on:
   merge_group:
   workflow_dispatch: {}
 
+permissions:
+  contents: read
+
 # A workflow run is made up of one or more jobs that can run sequentially or in parallel
 jobs:
   check-changes: