[TASK] Remove not maintained ChangeLog in EXT:linkvalidator

Resolves: #59738
Releases: 6.3
Change-Id: Idb08c3f7311ae97590495c77d180429baabefcda
Reviewed-on: https://review.typo3.org/30960
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer