Skip flaky undo/redo stack tests (microsoft#260514)

See microsoft#254041

Author: alexr00

extensions/vscode-api-tests/src/singlefolder-tests/editor.test.ts

@@ -173,7 +173,7 @@ suite('vscode API - editors', () => {
 		}, { undoStopBefore: undoStopBefore, undoStopAfter: undoStopAfter });
 	}
 
-	test('TextEditor.edit can control undo/redo stack 1', () => {
+	test.skip('TextEditor.edit can control undo/redo stack 1', () => {
 		return withRandomFileEditor('Hello world!', async (editor, doc) => {
 			const applied1 = await executeReplace(editor, new Range(0, 0, 0, 1), 'h', false, false);
 			assert.ok(applied1);
@@ -196,7 +196,7 @@ suite('vscode API - editors', () => {
 		});
 	});
 
-	test('TextEditor.edit can control undo/redo stack 2', () => {
+	test.skip('TextEditor.edit can control undo/redo stack 2', () => {
 		return withRandomFileEditor('Hello world!', (editor, doc) => {
 			return executeReplace(editor, new Range(0, 0, 0, 1), 'h', false, false).then(applied => {
 				assert.ok(applied);