Remove CSS & JS version from default WordPress setting

functions.php

// remove css js version
function remove_cssjs_ver( $src ) {
    if( strpos( $src, '?ver=' ) )
        $src = remove_query_arg( 'ver', $src );
    return $src;
}
add_filter( 'style_loader_src', 'remove_cssjs_ver', 10, 2 );
add_filter( 'script_loader_src', 'remove_cssjs_ver', 10, 2 );

Or

// Remove WP Version From Styles    
add_filter( 'style_loader_src', 'sdt_remove_ver_css_js', 9999 );
// Remove WP Version From Scripts
add_filter( 'script_loader_src', 'sdt_remove_ver_css_js', 9999 );

// Function to remove version numbers
function sdt_remove_ver_css_js( $src ) {
    if ( strpos( $src, 'ver=' ) )
        $src = remove_query_arg( 'ver', $src );
    return $src;
}