I am not quiet sure if this is needed but if you want to only add the custom action to the GridField action menu than you need to add the extra classes otherwise it would add it to the action menu and to the gridfield.
I found these errors while going through this tutorial,
missing ```use use SilverStripe\Forms\GridField\GridField;```
interface GridField_ActionMenuItem required parameters on getTitle() and getGroup()
incorrect if statement on getExtraData() - $field is not defined
- Stronger wording around "use composer"
- Consistent domain and email address naming
- Removed example for publishing non-composer modules (those shouldn't be encouraged)
- Removed instructions for installing modules from archives
[ci skip]
* WIP GridField action menu work, the gist of the idea is using a new gridfield component
* Add delete action to actions menu
* Actions are added automatically to action menu (allows for extension)
* Add test and minor changes
* Add docs and minor changes
* Refactor ActionMenuItem into distinct types, general ActionMenu cleanup
* Add icons and fix title
* Pass columnName, so it can be used by components
* Update test to open and find action menu buttons
* Add section in changelog upgrade section for GridField_ActionMenu