Add explicit permissions to GitHub workflow for security

Co-authored-by: taylortom <[email protected]>

Author: Copilot

.github/workflows/tests.yml

@@ -3,6 +3,8 @@ on: push
 jobs:
   default:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     steps:
       - uses: actions/checkout@master
       - uses: actions/setup-node@master