PHP8.1 deprecation

WordPress method wp_is_stream( $path ) in wp-includes/functions.php calls strpos($path, '://' ); but your plugin in some conditions calls wp_is_stream( $path ) with a null value, resulting in 2 php warning (php 8.1) when accessing wp-admin (maybe elsewhere too)

Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in /wp-includes/functions.php on line 7303
Deprecated: str_replace(): Passing null to parameter #3 ($subject) of type array|string is deprecated in /wp-includes/functions.php on line 2189

You can easily fix that by modifying the call to the method add_submenu_page() in /plugins/testimonial-widgets/testimonials-plugin.class.php

add_submenu_page(
    $v["hide"] ? null : $menu["home_page"],
    $v["title"],
    $k,
    $permission,
    $v["url"]
);

by

add_submenu_page(
    $v["hide"] ? "" : $menu["home_page"],
    $v["title"],
    $k,
    $permission,
    $v["url"]
);

you’re welcome ??