CI: add least-privilege permissions to GitHub Actions workflows (#270)

Refs: APPSEC-164

Co-authored-by: Peter Matkovski <matkovski@Peters-MBP.local>
Co-authored-by: Cursor <cursoragent@cursor.com>

Author: 3 people

.github/workflows/ci.yml

@@ -5,6 +5,10 @@ on:
   pull_request:
     branches: [ "**" ]
 
+permissions:
+  contents: read
+  pull-requests: read
+
 jobs:
   unit:
     uses: ./.github/workflows/run_tests.yml

.github/workflows/run_tests.yml

@@ -15,6 +15,9 @@ env:
   # If set, uv will run without updating the uv.lock file. Equivalent to the `uv run --frozen`.
   UV_FROZEN: "1"
 
+permissions:
+  contents: read
+
 jobs:
   ruff:
     name: Ruff