Generate a blogpost that does not require editing

What does this MR do and why?

I don't like editing the generate blogpost. Do you like it?

It takes time plus an extra CI run.

Can we credit all the releases to the delivery group instead?

This MR removes the manual edits from the multi version patch release post.

Example:

• gitlab-com/www-gitlab-com!115741 (diffs)
• https://ac-test-multivers-blog-post.about.gitlab-review.app/releases/2022/11/30/gitlab-15-6-1-15-5-1-15-4-1-released/

Author Check-list

• Has documentation been updated?