testing: implement retired test state

Fixes https://github.com/microsoft/vscode/issues/115086

src/vs/workbench/api/browser/mainThreadTesting.ts

@@ -51,6 +51,17 @@ export class MainThreadTesting extends Disposable implements MainThreadTestingSh
 		}
 	}
 
+	/**
+	 * @inheritdoc
+	 */
+	$retireTest(extId: string): void {
+		for (const result of this.resultService.results) {
+			if (result instanceof LiveTestResult) {
+				result.retire(extId);
+			}
+		}
+	}
+
 	/**
 	 * @inheritdoc
 	 */