JDK-8356688 enabled the SWT tests on Linux.

The following test failed one time on our headful Ubuntu 22.04 system:


> Task :swt:test FAILED

SWTCursorsTest > testImageCursor() FAILED
    org.opentest4j.AssertionFailedError: expected: not <null>
        at app//org.junit.jupiter.api.AssertionFailureBuilder.build(AssertionFailureBuilder.java:152)
        at app//org.junit.jupiter.api.AssertionFailureBuilder.buildAndThrow(AssertionFailureBuilder.java:132)
        at app//org.junit.jupiter.api.AssertNotNull.failNull(AssertNotNull.java:49)
        at app//org.junit.jupiter.api.AssertNotNull.assertNotNull(AssertNotNull.java:35)
        at app//org.junit.jupiter.api.AssertNotNull.assertNotNull(AssertNotNull.java:30)
        at app//org.junit.jupiter.api.Assertions.assertNotNull(Assertions.java:304)
        at app//test.javafx.embed.swt.SWTCursorsTest.lambda$testImageCursor$1(SWTCursorsTest.java:65)
        at app//org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
        at app//org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
        at app//org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:5039)
        at app//org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4519)
        at app//test.javafx.embed.swt.SWTCursorsTest.lambda$testImageCursor$0(SWTCursorsTest.java:71)
        at app//test.javafx.embed.swt.SWTTest.lambda$runOnSwtThread$0(SWTTest.java:52)
        at app//org.eclipse.swt.widgets.RunnableLock.run(RunnableLock.java:40)
        at app//org.eclipse.swt.widgets.Synchronizer.runAsyncMessages(Synchronizer.java:132)
        at app//org.eclipse.swt.widgets.Display.runAsyncMessages(Display.java:5039)
        at app//org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:4519)
        at app//test.javafx.embed.swt.SWTTest.runOnSwtThread(SWTTest.java:62)
        at app//test.javafx.embed.swt.SWTCursorsTest.testImageCursor(SWTCursorsTest.java:50)