🔒️ Add zizmor and fix audit findings (#2260)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.github/workflows/test-backend.yml

@@ -9,18 +9,27 @@ on:
       - opened
       - synchronize
 
+permissions: {}
+
 jobs:
   test-backend:
     runs-on: ubuntu-latest
+    timeout-minutes: 5
     steps:
       - name: Checkout
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
       - name: Set up Python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: "3.10"
       - name: Install uv
-        uses: astral-sh/setup-uv@37802adc94f370d6bfd71619e3f0bf239e1f3b78 # v7.6.0
+        uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
+        with:
+          # Before upgrading uv version, make sure astral-sh/setup-uv knows its checksum.
+          # See: https://github.com/astral-sh/setup-uv/issues/851#issuecomment-4282017837
+          version: "0.11.4"
       - run: docker compose down -v --remove-orphans
       - run: docker compose up -d db mailcatcher
       - name: Migrate DB