ci: set permission to read

Author: drgroot

.github/workflows/test.yml

@@ -5,6 +5,9 @@ on:
     branches:
       - main
 
+permissions:
+  contents: read
+
 jobs:
   unittest:
     runs-on: ubuntu-latest
@@ -62,4 +65,4 @@ jobs:
         run: |
           pip install coverage
           coverage run -m unittest tests/*.py
-          coverage report -m --fail-under=60
+          coverage report -m --fail-under=60