Add coverage dependency to 'unit' group in pyproject.toml file

.github/workflows/unit-tests.yml

@@ -51,7 +51,7 @@ jobs:
 
       - name: Check coverage
         run: |
-          coverage=$(uv run --python $PYTHON_VERSION coverage report -m | tail -1 | tail -c 4 | head -c 2)
+          coverage=$(uv run --python ${{ matrix.python }} --group unit coverage report -m | tail -1 | tail -c 4 | head -c 2)
           echo "Total coverage: ${coverage}%"
           
           # Check if coverage is below the threshold
@@ -59,5 +59,5 @@ jobs:
               echo "Coverage failed at ${coverage}%, expected at least 40%"
               exit 1
           else
-              echo "Coverage passed, ${coverage}%"
+              echo "Coverage check passed with ${coverage}%"
           fi