Make apps/web/playwright comply with strict mode (#34403)

* Make apps/web/playwright comply with strict mode

Otherwise it sometimes fails to compile matrix-js-sdk as strict mode & noImplicitAny both impact how overloads are asserted

* Iterate

apps/web/playwright/plugins/homeserver/synapse/legacyOAuthHomeserver.ts

@@ -22,12 +22,12 @@ export const legacyOAuthHomeserver: Fixtures = {
     ],
     context: async ({ homeserverType, context, oAuthServer }, use, testInfo) => {
         testInfo.skip(homeserverType !== "synapse", "does not yet support OIDC");
-        oAuthServer.onTestStarted(testInfo);
+        oAuthServer!.onTestStarted(testInfo);
         await use(context);
     },
     _homeserver: [
         async ({ oAuthServer, _homeserver: homeserver }, use) => {
-            const port = oAuthServer.start();
+            const port = oAuthServer!.start();
             await TestContainers.exposeHostPorts(port);
             homeserver.withConfig({
                 oidc_providers: [