PHPSTAN next minor warnings

In https://www.drupal.org/project/drupal/issues/3474533 ✨ ComponentPluginManager must implement CategorizingPluginManagerInterface Active the core's SDC plugin manager now also implements the CategorizingPluginManagerInterface and uses the \Drupal\Core\Plugin\CategorizingPluginManagerTrait like the \Drupal\ui_patterns\ComponentPluginManager but its processDefinitionCategory doesn't have the type hint for parameter.
The CategorizingPluginManagerTrait also doesn't specify a type hint, but overriding the trait's method with a different signature is allowed, while overriding the parent class method like that causes a critical error.
This prevents the module from working at all after the change from the mentioned issue.

It should be safe to just remove the type hint, so the method signature is the same as in the parent and trait.

Good for me.

Just wondering why existing tests are not failing on Core 11.1 without this MR.