fix removing ad banners

jest/lib.tsx

@@ -16,7 +16,7 @@ const PAGE_PROPS = {
   cookies: '',
   referrer: '',
   query: {},
-  adBannerProvider: undefined,
+  adBannerProvider: null,
   apiData: null,
 };
 

lib/contexts/app.tsx

@@ -12,7 +12,7 @@ const AppContext = createContext<PageProps>({
   cookies: '',
   referrer: '',
   query: {},
-  adBannerProvider: undefined,
+  adBannerProvider: null,
   apiData: null,
 });
 

nextjs/getServerSideProps.ts

@@ -14,7 +14,7 @@ export interface Props<Pathname extends Route['pathname'] = never> {
   query: Route['query'];
   cookies: string;
   referrer: string;
-  adBannerProvider: AdBannerProviders | undefined;
+  adBannerProvider: AdBannerProviders | null;
   // if apiData is undefined, Next.js will complain that it is not serializable
   // so we force it to be always present in the props but it can be null
   apiData: metadata.ApiData<Pathname> | null;
@@ -32,15 +32,15 @@ Promise<GetServerSidePropsResult<Props<Pathname>>> => {
         return adBannerFeature.provider;
       }
     }
-    return;
+    return null;
   })();
 
   return {
     props: {
       query,
       cookies: req.headers.cookie || '',
       referrer: req.headers.referer || '',
-      adBannerProvider,
+      adBannerProvider: adBannerProvider,
       apiData: null,
     },
   };