Filters get_terms() arguments when querying terms via the REST API.

The dynamic portion of the hook name, $this->taxonomy, refers to the taxonomy slug.

Possible hook names include:

• rest_category_query
• rest_post_tag_query

Enables adding extra arguments or setting defaults for a terms
collection request.

$prepared_args = apply_filters( "rest_{$this->taxonomy}_query", $prepared_args, $request );