How to alter Core Existing Actions using hook_action_info_alter

In Drupal 9 /10 We have a core Actions Plugin defined in docroot/core/lib/Drupal/Core/Action/ActionManager.php which is providing a hook to alter Action annotations, I used the below code to alter the existing Action Class with a New one

In your custom module add the below code in your my_module.module file

function module_name_action_info_alter(&$definitions) {

  // Overwrite Drupal Core Add Role class with CustomClass
  foreach ($definitions as &$definition) {
    // user_add_role_action is a core action, check           docroot/core/modules/user/src/Plugin/Action/AddRoleUser.php
    if ($definition['id'] === 'user_add_role_action' && $definition['class'] == AddRoleUser::class) {
      $definition['class'] = YourOwnClass::class; // we need to create YourOwnClass in docroot/modules/custom/module_name/src/Plugin/Action/YourOwnClass.php
    }
  }
}

If we print $definition for any action we see the below information

array:6 [▼
  "confirm_form_route_name" => ""
  "type" => "user"
  "id" => "user_add_role_action"
  "label" => Drupal\Core\StringTranslation\TranslatableMarkup {#33044 ▶}
  "class" => "Drupal\user\Plugin\Action\AddRoleUser"
  "provider" => "user"
]