This was already fixed as part of RN-35, released in 2.0.
The last $velocityCount usages were removed by 2 commits on master, both on 2021-04-02:
f4071b1 in Code/Change/ChangeDisplayerGrid.xml, Code/Change/ChangeDisplayerVelocityMacros.xml and Code/MigrationFrom1x.xml
322e20b ("Finish removing deprecated usage of $velocityCount") in Code/Change/GetChangesMacro.xml
All loops now use $foreach.count / $foreach.index instead. I verified on the current code base (2.4-SNAPSHOT) that no $velocityCount (nor $velocityHasNext) usage remains, neither in the -ui module nor in the -demo module. I also checked the source of the page mentioned in the description (ReleaseNotes.Data.XWiki.11.10.10.WebHome on xwiki.org) and it doesn't contain any $velocityCount either.