New GraphQL.js redirects do not work internally, and some links are broken

### Description

GraphQL.js webpages are still included in the website, and are still searchable and navigable. However, when you reload the page you are sent to GraphQL-js.org and the webpage doesn't necessarily exist.

### Steps to Reproduce

1. Visit https://graphql.org/
2. Enter "Running an Express GraphQL Server" into the search bar and press the top link
3. Notice that you have been directed to `https://graphql.org/graphql-js/running-an-express-graphql-server/` and a web page is rendered
4. Reload the page (or visit `https://graphql.org/graphql-js/running-an-express-graphql-server/` directly)
5. Notice that you have been redirected to `https://www.graphql-js.org/running-an-express-graphql-server/` and greeted with a 404.

### Expected Result

In step 3 you should be directed to graphql-js.org (or the search result should not appear in the first place?)

If you visit `https://graphql.org/graphql-js/running-an-express-graphql-server/` directly, you should be redirected to an extant page on `graphql-js.org`

### Actual Result

Old content rendered in step 3.

404 rendered in step 5.

Reproduce the redirect using the graphql.org homepage, search result, and direct URL described in the issue. Trace the website routing and search handling for the /graphql-js/running-an-express-graphql-server/ path; done means the old page is no longer served and direct visits resolve to an existing graphql-js.org page.

Vom Indexierungsmodell aus dem Issue-Text verfasst.