Removing transition offer from banner

What does this MR do and why?

This MR effectively reverts Adding offer details into the enforcement banner (!122522 - merged) and Moving one-time discount to the correct banner (!122964 - merged).

Removing promotional offer for user limits (gitlab-com/www-gitlab-com!128279 - merged) updates the FAQ and T&Cs to remove the offer as well.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.