WordPress — Remove 'type' Attribute of Scripts and Styles

functions.php

<?php

if ( ! function_exists( 'prefix_remove_type_attr' ) ) {

	/**
	 * Remove 'type' Attribute of Scripts and Styles
	 */
	function prefix_remove_type_attr( $tag ) {
		return preg_replace( "/type=['\"]text\/(javascript|css)['\"]/", '', $tag );
	}

	add_filter( 'style_loader_tag', 'prefix_remove_type_attr', 10 );
	add_filter( 'script_loader_tag', 'prefix_remove_type_attr', 10 );
	add_filter( 'autoptimize_html_after_minify', 'prefix_remove_type_attr', 10 ); // 'Autoptimize' plugin support

}