Suppress the upgrade in progress message

From semantic-mediawiki.org
Information status about the upgrade progress

How can I suppress it?

09:18, 23 August 2020

Not at all.

12:14, 23 August 2020

Great. Then does this page have some HTTP header or response code, so that I can tell the frontend not to pollute the cache with it?

13:55, 23 August 2020