testSetInvalidCreatingDescription (org.eclipse.cdt.core.settings.model.CProjectDescriptionBasicTests) is a flaky test

[jonahgraham]

testSetInvalidCreatingDescription (org.eclipse.cdt.core.settings.model.CProjectDescriptionBasicTests) is flaky

It has been for a while, but no issue has been created until now. e.g. #645 (comment) and https://github.com/eclipse-cdt/cdt/pull/1003/checks?check_run_id=35606369537 are examples of fails.