Remove default value from --format parameter to prevent auto-population

WP-CLI's parameter parser uses the 'default' value in docblocks to
automatically populate parameters. Removing 'default: table' ensures
--format is only set when explicitly provided by the user, preserving
backward compatibility with existing commands that don't use --format.

Co-authored-by: swissspidy <[email protected]>

Author: Copilot

src/Core_Language_Command.php

@@ -186,7 +186,6 @@ public function is_installed( $args ) {
 	 * [--format=<format>]
 	 * : Render output in a particular format. Used when installing multiple languages.
 	 * ---
-	 * default: table
 	 * options:
 	 *   - table
 	 *   - csv