Update the docs monthly release process

We no longer need to update the 404 links anymore.

doc/development/documentation/site_architecture/release_process.md

@@ -128,16 +128,6 @@ version and rotates the old one:
    - `online`: The 3 latest stable versions.
    - `offline`: All the previous versions offered as an offline archive.
 
-1. **Add the new offline version in the 404 page redirect script:**
-
-   Since we're deprecating the oldest version each month, we need to redirect
-   those URLs in order not to create [404 entries](https://gitlab.com/gitlab-org/gitlab-docs/issues/221).
-   There's a temporary hack for now:
-
-   1. Edit `content/404.html`, making sure all offline versions under
-      `content/_data/versions.yaml` are in the JavaScript snippet at the end of
-      the document.
-
 1. **Update the `:latest` and `:archives` Docker images:**
 
    The following two Dockerfiles need to be updated: