Update actions/checkout action to v6

.github/workflows/python-app.yml

@@ -34,7 +34,7 @@ jobs:
     runs-on: ubuntu-24.04
 
     steps:
-    - uses: actions/checkout@v5
+    - uses: actions/checkout@v6
       with:
         fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
     - name: Set up Python 3.13

app/requirements-test.txt

@@ -2,7 +2,7 @@
     pytest==8.4.2
     pytest-asyncio==1.2.0
     pytest-cov==7.0.0
-    python-dotenv==1.2.1
+    python-dotenv==1.1.1
     mock==5.2.0
     coverage==7.10.7
     jinja2-cli==0.8.2