fix: Set top-level permissions for e2e reusable workflow (#2052)

Signed-off-by: Ian Lewis <ianlewis@google.com>

Author: ianlewis

.github/workflows/e2e.verify-token.reusable.yml

@@ -3,6 +3,8 @@ name: verify-token schedule
 on:
   workflow_call:
 
+permissions: read-all
+
 env:
   GH_TOKEN: ${{ github.token }}
   ISSUE_REPOSITORY: ${{ github.repository }}