Removes jQuery Migrate script from WordPress. Reason: modern browsers don't need this anymore.

remove-jquery-migrate-wordpress.php

<?php
/**
 * Remove jQuery Migrate script
 */
function ryno_remove_jquery_migrate( $scripts ) {
	if ( isset( $scripts->registered['jquery'] ) ) {
		$script = $scripts->registered['jquery'];

		if ( $script->deps ) { // Check whether the script has any dependencies
			$script->deps = array_diff( $script->deps, array( 'jquery-migrate' ) );
		}
	}
}
add_action( 'wp_default_scripts', 'ryno_remove_jquery_migrate' );