Conform more code to strictNullChecks (#10383

* Update matrix-widget-api

* Conform more code to `strictNullChecks`

* Iterate

src/utils/WidgetUtils.ts

@@ -450,7 +450,7 @@ export default class WidgetUtils {
         oobRoomName?: string,
     ): Promise<void> {
         const domain = Jitsi.getInstance().preferredDomain;
-        const auth = await Jitsi.getInstance().getJitsiAuth();
+        const auth = (await Jitsi.getInstance().getJitsiAuth()) ?? undefined;
         const widgetId = randomString(24); // Must be globally unique
 
         let confId;