A script can create a change for a release note that does not exist

Steps to reproduce

1. In a wiki with no release note for the version 9.9 of XWiki, run as a user who may edit the ReleaseNotes.Data space:

   {{velocity}}
   #set ($reference = $services.releasenotes.createChange({'product': 'XWiki', 'version': '9.9', 'title': 'Orphan'}))
   $reference
   {{/velocity}}
   

Expected

The call fails, as POST /rest/wikis/xwiki/releasenotes/XWiki/9.9/changes does (404 "There is no release note for the version [9.9] of [XWiki].").

Actual

The change is created in ReleaseNotes.Data.XWiki.9\.9.Entry001.WebHome, under a release note page that does not exist. No release note lists it, and the space is left with an orphan page.

The REST endpoint checks that the release note exists before creating a change, while the script service goes straight to the change manager.