Change patch info from 15.11.1 to ???

Thanks to the information in this thread !123444 (comment 1367275922) we know that the fix for Failure in update_major test (gitlab-org/gitlab#408304 - closed) is not coming out in 15.11.1, because that patch release contains only security fixes. We're not sure if it will be 15.11.2 or a different release number, but the right answer is to not be quite so definite on when it will be fixed.

Folks who have been following along with the progress of this fix: @jon_jenkins, @bprescott_, @alexives.

Related issues

• Related to Failure in update_major test (gitlab-org/gitlab#408304 - closed)
• Reverses the change from Update 15.11 release message (!123444 - merged) and adding a bit of extra language to point to the patch releases page instead of saying a specific release number
• Related to Use less specific language about DB fix version (gitlab-org/gitlab!119571 - merged) which updates the Upgrades page in the documentation. (Different repo, so can't be done in the same merge request.)