Unskip failing cross section test

Remove the skip marker from the 'test_missing_cross_section' test, enabling it to run. Added a cleanup step to delete 'main_window' at the end of the test to ensure proper resource deallocation.

Signed-off-by: Jose Borreguero <[email protected]>

test/ui/test_missing_cross_section.py

@@ -12,7 +12,7 @@
 TEST_REFLECTIVITY_THRESHOLD_VALUE = 0.01
 
 
-@pytest.mark.skip("Test fails in the CI pipeline, see EWM 7743")
+#@pytest.mark.skip("Test fails in the CI pipeline, see EWM 7743")
 @pytest.mark.datarepo
 def test_missing_cross_section(qtbot):
     r"""Test a run where the crossection corresponding to the On-On spin combination has no integrated
@@ -33,7 +33,7 @@ def test_missing_cross_section(qtbot):
     # check the x vs TOF plot has changed
     intensity_on_on = np.sum(ui_utilities.data_from_plot2D(main_window.xtof_overview))
     assert intensity_on_on / intensity_off_on < TEST_REFLECTIVITY_THRESHOLD_VALUE
-
+    del main_window
 
 if __name__ == "__main__":
     pytest.main([__file__])