CI: update/pin actions + fix zizmor warnings

Author: lazka

.github/workflows/main.yml

@@ -2,17 +2,23 @@ name: test
 
 on: [push, pull_request, workflow_dispatch]
 
+permissions: {}
+
 jobs:
   test:
     runs-on: ubuntu-latest
+    permissions:
+      contents: read
     strategy:
       fail-fast: false
       matrix:
         python-version: ['3.11', '3.12', '3.13', '3.14']
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      with:
+        persist-credentials: false
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v5
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies
@@ -36,7 +42,9 @@ jobs:
     runs-on: ubuntu-latest
     if: (github.repository == 'msys2/msys2-web' && github.event_name == 'push' && github.ref == 'refs/heads/main')
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          persist-credentials: false
       - name: Log in
         run: |
           echo "$TOKEN" | docker login ghcr.io --username "$USERNAME" --password-stdin