frontend-scripts.php

<?php 
blockgallery_frontend_scripts() {
	if ( has_block( 'blockgallery/masonry' ) ) {
		wp_enqueue_script(
			'blockgallery-masonry',
        		plugins_url( 'dist/blockgallery-masonry.js', __FILE__ ),
			array( 'jquery', 'masonry', 'imagesloaded' ),
			filemtime( plugin_dir_path( __FILE__ ) . 'dist/blockgallery-masonry.js' )
		);
	}
}
add_action( 'wp_enqueue_scripts', 'blockgallery_frontend_scripts' );