Add xvfb for linux tests (#26)

Author: paulacamargo25

.github/workflows/push-check.yml

@@ -95,6 +95,13 @@ jobs:
         run: python -m pip install -U pip pipx wheel
         shell: bash
 
+      - name: Start xvfb on Linux
+        run: |
+          /usr/bin/Xvfb :99 -screen 0 1024x768x24 > /dev/null 2>&1 &
+          echo "DISPLAY=:99" >> $GITHUB_ENV
+          echo ">>> Started xvfb"
+        if: ${{ runner.os }} == 'Linux'
+
       - name: Run tests
         run: pipx run nox --session tests
         shell: bash