Get the attached media to a post minus the featured image

GetAttachedMediaMinusFeaturedImage.php

function GetAttachedMediaMinusFeaturedImage( INT $postId ) {

	$featuredImage = get_post_thumbnail_id( $postId );
	$attached_media = get_attached_media( NULL, $postId );

	unset( $attached_media[ $featuredImage ] );

	return $attached_media;

}