Remove unwanted Scripts and css

// CHILD functions.php
 
add_action( 'wp_print_scripts', 'child_overwrite_scripts', 100 );
add_action( 'wp_print_styles', 'child_overwrite_styles', 100 );
 
function child_overwrite_scripts() {
    wp_deregister_script( 'fancybox-parent-js' );
}
 
function child_overwrite_styles() {
    wp_deregister_style( 'fancybox-parent-css' );
}