Replace calls to ResourceTest.cleanup()

Some test classes manually call the cleanup() method of ResourceTest
just to remove the projects in the workspace. Since this method contains
more functionality than that and should be private to the ResourceTest
teardown functionality, this change replaces the calls to the method
with ordinary cleanups of the workspace.

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/internal/builders/ParallelBuildChainTest.java

@@ -105,7 +105,8 @@ protected void setUp() throws Exception {
 	@Override
 	protected void tearDown() throws Exception {
 		// Cleanup workspace first to ensure that auto-build is not started on projects
-		cleanup();
+		waitForBuild();
+		getWorkspace().getRoot().delete(true, true, getMonitor());
 		super.tearDown();
 		TimerBuilder.abortCurrentBuilds();
 	}
@@ -143,7 +144,7 @@ public void testIndividualProjectBuilds_ProjectRelaxedRule() throws Exception {
 
 	@Test
 	public void testIndividualProjectBuilds_WithManyProjects_ProjectRelaxedRule() throws Exception {
-		int numberOfParallelBuilds = 60;
+		int numberOfParallelBuilds = 30;
 		var longRunningProjects = createMultipleTestProjects(numberOfParallelBuilds, BuildDurationType.LONG_RUNNING,
 				RuleType.CURRENT_PROJECT_RELAXED);
 		executeIndividualFullProjectBuilds(numberOfParallelBuilds, () -> {

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/IResourceTest.java

@@ -471,7 +471,8 @@ protected void reinitializeProjectsAfterTestIteration() {
 		public void cleanUp(Object[] args, int countArg) throws Exception {
 			// Reinitialize projects if necessary
 			if (reinitializeOnCleanup) {
-				IResourceTest.this.cleanup();
+				waitForBuild();
+				getWorkspace().getRoot().delete(true, true, getMonitor());
 				IResourceTest.this.initializeProjects();
 				reinitializeOnCleanup = false;
 			}

resources/tests/org.eclipse.core.tests.resources/src/org/eclipse/core/tests/resources/ResourceTest.java

@@ -428,7 +428,7 @@ public IResource[] buildResources(IContainer root, String[] hierarchy) {
 		return result;
 	}
 
-	protected void cleanup() throws CoreException {
+	private void cleanup() throws CoreException {
 		// Wait for any build job that may still be executed
 		waitForBuild();
 		final IFileStore[] toDelete = storesToDelete.toArray(new IFileStore[0]);