fix: leaking event listeners (microsoft#209036)

Fixes microsoft#207466
Fixes microsoft#207556

Author: connor4312

src/vs/workbench/contrib/testing/browser/testingDecorations.ts

@@ -174,7 +174,7 @@ export class TestingDecorationService extends Disposable implements ITestingDeco
 		super();
 		codeEditorService.registerDecorationType('test-message-decoration', TestMessageDecoration.decorationId, {}, undefined);
 
-		modelService.onModelRemoved(e => this.decorationCache.delete(e.uri));
+		this._register(modelService.onModelRemoved(e => this.decorationCache.delete(e.uri)));
 
 		const debounceInvalidate = this._register(new RunOnceScheduler(() => this.invalidate(), 100));
 

src/vs/workbench/contrib/testing/browser/testingOutputPeek.ts

@@ -997,11 +997,11 @@ class TestResultsPeek extends PeekViewWidget {
 
 	protected override _fillBody(containerElement: HTMLElement): void {
 		this.content.fillBody(containerElement);
-		this.content.onDidRequestReveal(sub => {
+		this._disposables.add(this.content.onDidRequestReveal(sub => {
 			TestingOutputPeekController.get(this.editor)?.show(sub instanceof MessageSubject
 				? sub.messageUri
 				: sub.outputUri);
-		});
+		}));
 	}
 
 	/**