Accessibility: Remove the revisions limit title attribute from the Publish box.

The revisions limit warning is now always displayed in plain text even when the
limit is not reached yet. Removes the plus "+" from the revisions count number.

Fixes #35029.
Built from https://develop.svn.wordpress.org/trunk@36053


git-svn-id: https://core.svn.wordpress.org/trunk@36018 1a063a9b-81f0-0310-95a4-ce76da25c4cd