Add error check when commands are not found in cmd_dump

Co-authored-by: swissspidy <841956+swissspidy@users.noreply.github.com>

Author: Copilot

features/scaffold-package-readme.feature

@@ -294,7 +294,6 @@ Feature: Scaffold a README.md file for an existing package
       *This README.md is generated dynamically from the project's codebase
       """
 
-  @broken
   Scenario: Error when commands are specified but not present
     Given an empty directory
     And a foo/composer.json file:

src/ScaffoldPackageCommand.php

@@ -332,12 +332,9 @@ public function package_readme( $args, $assoc_args ) {
 					}
 				} while ( $parent_command && $bits );
 
-				/* This check doesn't work because of the way the commands are fetched.
-				 * Needs bigger refactor to put this check back in.
 				if ( empty( $parent_command ) ) {
 					WP_CLI::error( 'Missing one or more commands defined in composer.json -> extra -> commands.' );
 				}
-				 */
 
 				$longdesc = isset( $parent_command['longdesc'] ) ? $parent_command['longdesc'] : '';
 				$longdesc = (string) preg_replace( '/## GLOBAL PARAMETERS(.+)/s', '', $longdesc );