Fixes #123882

The catch block around the return statement was never executing, as it would catch only synchronous errors thrown by `_doHandleExtensionTests`. By awaiting the returned promise, we make sure to catch also promise rejections, which gives us a chance to log the error message on the extension host console as well.

src/vs/workbench/api/common/extHostExtensionService.ts

@@ -551,7 +551,7 @@ export abstract class AbstractExtHostExtensionService extends Disposable impleme
 	public async $extensionTestsExecute(): Promise<number> {
 		await this._eagerExtensionsActivated.wait();
 		try {
-			return this._doHandleExtensionTests();
+			return await this._doHandleExtensionTests();
 		} catch (error) {
 			console.error(error); // ensure any error message makes it onto the console
 			throw error;