The generate_page_hero_post_author allows us to alter the HTML of the post author when using {{post_author}} template tag in header element.
Example
If we don』t want a link surrounding the post author:
add_filter( 'generate_page_hero_post_author', function() {
global $post;
$author_id = $post->post_author;
return sprintf( '',
esc_html( get_the_author_meta( 'display_name', $author_id ) )
);
} );