fix: resolve CI apt-get pip installation issues

Use 'python -m pip' and 'python -m pytest' commands for better
compatibility with Gitea Actions environment

.gitea/workflows/ci.yml

@@ -21,11 +21,11 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip setuptools wheel
-          pip install pytest pytest-cov
-          pip install -e .
+          python -m pip install pytest pytest-cov
+          python -m pip install -e .
 
       - name: Run tests
-        run: pytest confsync/tests/ -v --tb=short
+        run: python -m pytest confsync/tests/ -v --tb=short
 
   lint:
     runs-on: ubuntu-latest
@@ -39,10 +39,10 @@ jobs:
           cache: 'pip'
 
       - name: Install ruff
-        run: pip install ruff
+        run: python -m pip install ruff
 
       - name: Run ruff
-        run: ruff check .
+        run: python -m ruff check .
 
   typecheck:
     runs-on: ubuntu-latest
@@ -56,7 +56,7 @@ jobs:
           cache: 'pip'
 
       - name: Install mypy
-        run: pip install mypy
+        run: python -m pip install mypy
 
       - name: Run mypy
-        run: mypy confsync/ --ignore-missing-imports
+        run: python -m mypy confsync/ --ignore-missing-imports