Remove OpenCloseTest from UiTestSuite

OpenCloseTest is a stress test that repeatedly opens and closes editors,
views, perspectives, workbench windows and the intro part. On the macOS CI
runners it is the single most expensive test (about 290s, roughly 29% of the
whole org.eclipse.ui.tests suite) and it intermittently stalls in
testOpenClosePerspective for 8 to 9 minutes, which kills the forked test VM
through the per-bundle timeout. The watchdog added earlier only turns that
stall into a fast failure; it removes neither the cost nor the flakiness.

The open/close cycles it exercises are already covered functionally and for
leaks elsewhere, for example LeakTests (testSimpleEditorLeak,
testSimpleViewLeak, testSimpleWindowLeak), IWorkbenchPageTest, the zoom
ShowView and OpenEditor tests and the intro tests. Removing it from the suite
loses no real coverage while reclaiming a large, variable chunk of the macOS
validation time. The test class is kept for manual stress testing.

Fixes #4101

Author: vogella

tests/org.eclipse.ui.tests/Eclipse UI Tests/org/eclipse/ui/tests/UiTestSuite.java

@@ -54,7 +54,6 @@
 import org.eclipse.ui.tests.releng.PluginActivationTests;
 import org.eclipse.ui.tests.services.ServicesTestSuite;
 import org.eclipse.ui.tests.statushandlers.StatusHandlingTestSuite;
-import org.eclipse.ui.tests.stress.OpenCloseTest;
 import org.eclipse.ui.tests.systeminplaceeditor.OpenSystemInPlaceEditorTest;
 import org.eclipse.ui.tests.themes.ThemesTestSuite;
 import org.eclipse.ui.tests.zoom.ZoomTestSuite;
@@ -108,7 +107,6 @@
 	WorkbenchDatabindingTest.class,
 	ChooseWorkspaceDialogTests.class,
 	ViewerItemsLimitTest.class,
-	OpenCloseTest.class,
 	WorkspaceLockTest.class
 })
 public class UiTestSuite {