Disable test_software_rendering on macOS

For some reason, macOS doesn't care about us disabling software rendering

tests/end2end/test_invocations.py

@@ -379,6 +379,7 @@ def test_qute_settings_persistence(short_tmpdir, request, quteproc_new):
 
 @pytest.mark.no_xvfb
 @pytest.mark.no_ci
+@pytest.mark.not_mac
 def test_force_software_rendering(request, quteproc_new):
     """Make sure we can force software rendering with -s."""
     if not request.config.webengine: