CI: Drop xvfb wrapping, surfplot not used yet

Author: effigies

.github/workflows/pythonpackage.yml

@@ -184,10 +184,8 @@ jobs:
     - name: Install test dependencies
       run: python -m pip install "niworkflows[tests]"
     - name: Run tests
-      uses: GabrielBB/xvfb-action@v1
-      with:
-        run: pytest -sv --no-xvfb --doctest-modules --cov niworkflows niworkflows
-    - uses: codecov/codecov-action@v2
+      run: pytest -sv --doctest-modules --cov niworkflows niworkflows
+    - uses: codecov/codecov-action@v3
       name: Submit to CodeCov
 
   test-pre:
@@ -269,10 +267,8 @@ jobs:
     - name: Install test dependencies
       run: python -m pip install $PIP_FLAGS "niworkflows[tests]"
     - name: Run tests
-      uses: GabrielBB/xvfb-action@v1
-      with:
-        run: pytest -sv --no-xvfb --doctest-modules --cov niworkflows niworkflows
-    - uses: codecov/codecov-action@v2
+      run: pytest -sv --doctest-modules --cov niworkflows niworkflows
+    - uses: codecov/codecov-action@v3
       name: Submit to CodeCov
 
   flake8: