Fix sporadic MarkerTest.testMarkerDeltasMoveFile failure

The test performed two separate IFile.move() calls, creating a window
where background jobs (e.g. charset/encoding validation) could acquire
the workspace lock between the two moves and fire resource change events
that added unexpected marker deltas for subFile. This caused the
listener to record 2 changes for /MyProject/folder/subFile.txt while
the test expected exactly 1.

Fix: wrap both moves in a single IWorkspaceRunnable so the workspace
lock is held throughout both operations, preventing background jobs
from interleaving and ensuring a single coalesced event with exactly
the 4 expected changes.

To reproduce the race before the fix, run the test ~200 times in a loop:
  mvn -pl resources/tests/org.eclipse.core.tests.resources \
      -Pbuild-individual-bundles \
      -Dtest=MarkerTest#testMarkerDeltasMoveFile \
      -Dsurefire.rerunFailingTestsCount=0 \
      verify
and repeat the invocation 200 times; the failure should appear within
that many iterations. With the fix, 200 runs should all succeed.

Co-authored-by: fedejeanne <2205684+fedejeanne@users.noreply.github.com>

Author: Copilot

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

@@ -969,9 +969,13 @@ public void testMarkerDeltasMoveFile(TestInfo testInfo) throws CoreException {
 		IMarker subFileMarker = subFile.createMarker(IMarker.BOOKMARK);
 		listener.reset();
 
-		// move the files
-		file.move(destFile.getFullPath(), IResource.FORCE, createTestMonitor());
-		subFile.move(destSubFile.getFullPath(), IResource.FORCE, createTestMonitor());
+		// move the files in one atomic workspace operation to prevent background jobs
+		// (e.g. charset/encoding validation) from running between the two moves and
+		// adding unexpected marker changes to the listener
+		getWorkspace().run(monitor -> {
+			file.move(destFile.getFullPath(), IResource.FORCE, monitor);
+			subFile.move(destSubFile.getFullPath(), IResource.FORCE, monitor);
+		}, createTestMonitor());
 
 		// verify marker deltas
 		listener.assertNumberOfAffectedResources(4);