Apparently I have to call the following `add_action` trigger to modify a custom post type metabox form to allow for multipart handling:

`add_action('post_edit_form_tag', [__CLASS__,'form_multipart_encoding'])`

But in this `add_action` logic of my plugin, I don't have access to $post, `get_the_ID()`, etc. How is it possible to only fire this action when in admin screen viewing my certain CPT?