**Description** Create a dedicated route to delete a translation for an entity. When triggered, the route should delete the selected non-default language translation while preserving the source language entity and all remaining translations. We will need 1 route for Canvas Pages, content entities, and 1 route for config entities Content Templates and Page regions. Patterns are not translatable. The UI that will use this route is being created in https://git.drupalcode.org/project/canvas/-/work_items/3591459 **Acceptance Criteria** - A dedicated delete translation route exists for translatable entities. - The route deletes only the selected translation. - The source/default language entity remains unchanged after deletion. - Other existing translations remain unaffected after deletion. - The translation is no longer available after successful deletion. - Proper access/permission checks are enforced before deletion.