Remove pytest-xdist

.github/workflows/main.yml

@@ -72,7 +72,7 @@ jobs:
         pip install --upgrade pip
         pip install ${{ matrix.qt-version }} numpy${{ matrix.numpy-version }} scipy pyopengl h5py matplotlib numba
         pip install .
-        pip install pytest pytest-cov pytest-xdist coverage
+        pip install pytest pytest-cov coverage
     - name: "Install Linux VirtualDisplay"
       if: runner.os == 'Linux'
       run: |
@@ -107,7 +107,6 @@ jobs:
       run: |
         mkdir $SCREENSHOT_DIR
         pytest pyqtgraph examples -v \
-          -n auto \
           --junitxml pytest.xml \
           --cov pyqtgraph --cov-report=xml --cov-report=html
       shell: bash