GSC custom search plugin – wp debug error

Hi

getting error on admin panel, and posts, with debug on

Notice: The called constructor method for WP_Widget in CGS_Widget is deprecated since version 4.3.0! Use
__construct()
instead. in /var/www/vhosts/MYSITE.ooo/httpdocs/wire/wp-includes/functions.php on line 3718 Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'CustomGoogleSearch' does not have a method 'add_js_css' in /var/www/vhosts/MYSITE.ooo/httpdocs/wire/wp-includes/plugin.php on line 525

Since I’m not actually using the widget, will plugin still work for the rest if I disable the line 12 in plugin

include_once( dirname( __FILE__ ) . '/widget.php' );

so as to not load the widget setup coding?