fix: resolve mypy type checking CI failure

.gitea/workflows/ci.yml

@@ -11,17 +11,17 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
-      
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install -e ".[dev]"
-      
+
       - name: Run tests
         run: pytest tests/ -v --cov=depnav --cov-report=term-missing
 
@@ -36,23 +36,23 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      
+
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: '3.11'
           cache: 'pip'
-      
+
       - name: Install dependencies
         run: |
           pip install --upgrade pip
           pip install .
-      
+
       - name: Build package
         run: |
           pip install build
           python -m build
-      
+
       - name: Upload package
         uses: actions/upload-artifact@v4
         with: