Restrict permissions to GitHub actions (#509)

Author: leszekhanusz

.github/workflows/lint.yml

@@ -1,5 +1,8 @@
 name: Lint
 
+permissions:
+  contents: read
+
 on: [push, pull_request]
 
 jobs:

.github/workflows/tests.yml

@@ -1,5 +1,8 @@
 name: Tests
 
+permissions:
+  contents: read
+
 on: [push, pull_request]
 
 jobs:
@@ -60,6 +63,10 @@ jobs:
   coverage:
     runs-on: ubuntu-24.04
 
+    permissions:
+      contents: read
+      checks: write
+
     steps:
       - uses: actions/checkout@v4
       - name: Set up Python 3.12