Revert "add xfail mark to test_qt_image_qapplication.py::test_sanity"

This reverts commit 380a697.

Author: radarhere

Tests/test_qt_image_qapplication.py

@@ -51,7 +51,6 @@ def roundtrip(expected):
     assert_image_similar(result, expected.convert("RGB"), 0.3)
 
 
-@pytest.mark.xfail(reason="Flaky test")
 @pytest.mark.skipif(not ImageQt.qt_is_installed, reason="Qt bindings are not installed")
 def test_sanity(tmp_path):
     # Segfault test