Random failing org.eclipse.core.tests.resources.CharsetTest.testDeltasContainer

[HeikoKlare]

The test case org.eclipse.core.tests.resources.CharsetTest.testDeltasContainer randomly fails, e.g. https://github.com/eclipse-platform/eclipse.platform/pull/583/checks?check_run_id=15291909544

Verifier has not yet been given a resource delta
java.lang.AssertionError: Verifier has not yet been given a resource delta
	at org.junit.Assert.fail(Assert.java:89)
	at org.eclipse.core.tests.resources.ResourceDeltaVerifier.isDeltaValid(ResourceDeltaVerifier.java:536)
	at org.eclipse.core.tests.resources.CharsetTest$MultipleDeltasCharsetVerifier.assertExpectedDeltasWereReceived(CharsetTest.java:1508)
	at org.eclipse.core.tests.resources.CharsetTest.testDeltasContainer(CharsetTest.java:1136)

The issue of a ResourceVerifier not being notified about changes has already been an issue with other related test cases:

• #99
• #319