Issue #3230668: Split out Composer Stager wiring into Package Manager submodule

package_manager/tests/modules/package_manager_bypass/src/Beginner.php

 <?php
 
-namespace Drupal\composer_stager_bypass;
+namespace Drupal\package_manager_bypass;
 
 use PhpTuf\ComposerStager\Domain\BeginnerInterface;
 use PhpTuf\ComposerStager\Domain\Output\ProcessOutputCallbackInterface;