fix(trashbin): drop the negative clause from expire help

Per @come-nc: the help should describe what the command does, not enumerate
what it does not do.

Author: mvanhorn

apps/files_trashbin/lib/Command/ExpireTrash.php

@@ -38,7 +38,7 @@ protected function configure(): void {
 		$this
 			->setName('trashbin:expire')
 			->setDescription('Delete expired files from the trashbin')
-			->setHelp('Deletes expired files from the trashbin according to the configured retention and space policy. This does not disable the trashbin or unconditionally empty it.')
+			->setHelp('Deletes expired files from the trashbin according to the configured retention and space policy.')
 			->addArgument(
 				'user_id',
 				InputArgument::OPTIONAL | InputArgument::IS_ARRAY,