Update Asciidoc build messaging to align with updated engineering maintenance policy

[karenzone]

"With the release of 8.16, we are also enhancing our Engineering Maintenance Policy. Elastic will now maintain the most current minor version as well as the previous minor version. This change increases the time customers can remain on a recent minor version and continue receiving maintenance updates. This is huge for our customers."

• Priority 1: Remove the "no additional bug fixes or documentation updates" messaging for the previous minor. This messaging directly contradicts the new maintenance policy.

  

• Evaluate pros and cons of including the previous minor in the version dropdown. Consider SEO and other implications.

  

• Communicate to all Docs team members that we should be backporting to the previous minor in addition to current version.

[karenzone]

Updated to show current messaging

This statement is not accurate, and should be updated or removed for supported versions.

[bmorelli25]

For engineering implementation:

8.19 and 8.18 need to be old not dead for the correct language to appear on each version:

https://github.com/elastic/docs/blame/a85b4f19b038b91f52639343f4406d446afeca0a/lib/ES/Book.pm#L18

[bmorelli25]

Evaluate pros and cons of including the previous minor in the version dropdown. Consider SEO and other implications.

I think this should be its own issue for discussion.

[florent-leborgne]

How can we prioritize this issue to get better language in the various banners?

This is coming back frequently enough IMO (example: https://elastic.slack.com/archives/C05PP2LEC1X/p1761259193664799)

[KOTungseth]

Total views of the 7.17 /guide in the last year are 928,552.

Out of the total 16,455,088 /guide views in the last year, 7.17 accounts for 5.6% of /guide views. However, a little under 1M views is not a small number.

Our immediate change is to update the banner text. We need to discuss our medium term plan for EOL /guide docs.