Improve performance of mock tests

ts/components/Intl.tsx

@@ -8,7 +8,6 @@ import type { FormatXMLElementFn } from 'intl-messageformat';
 import type { LocalizerType } from '../types/Util';
 import type { ReplacementValuesType } from '../types/I18N';
 import * as log from '../logging/log';
-import { strictAssert } from '../util/assert';
 
 export type FullJSXType =
   | FormatXMLElementFn<JSX.Element | string>
@@ -36,16 +35,6 @@ export function Intl({
     return null;
   }
 
-  strictAssert(
-    !localizer.isLegacyFormat(id),
-    `Legacy message format is no longer supported ${id}`
-  );
-
-  strictAssert(
-    !Array.isArray(components),
-    `components cannot be an array for ICU message ${id}`
-  );
-
   const intl = localizer.getIntl();
   return <>{intl.formatMessage({ id }, components, {})}</>;
 }