MM-27007 Remove automatic sidebar migration (#15087)

* MM-27007 Add migration of favorited channels to CreateInitialSidebarCategories

* MM-27007 Rewrite migrateFavortitesToSidebarT to use ROW_NUMBER() when available

* MM-27007 Remove automatic sidebar migration

* Remove old i18n strings

* Fix typo

* Address feedback

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

migrations/migrations.go

@@ -32,7 +32,6 @@ func init() {
 func MakeMigrationsList() []string {
 	return []string{
 		model.MIGRATION_KEY_ADVANCED_PERMISSIONS_PHASE_2,
-		model.MIGRATION_KEY_SIDEBAR_CATEGORIES_PHASE_2,
 	}
 }