ci: Limit GitHub token permissions for workflows.

This limits the ability for an Action to do mischief with this token.

Fixes #22786.

Signed-off-by: Varun Sharma <varunsh@stepsecurity.io>

.github/workflows/production-suite.yml

@@ -33,6 +33,9 @@ defaults:
   run:
     shell: bash
 
+permissions:
+  contents: read
+
 jobs:
   production_build:
     # This job builds a release tarball from the current commit, which