How to remove query parameter from url by parameter name in PHP

function.php

/* Function to remove query parameter by name*/
function removeQueryParam($url, $key)
{
    return preg_replace('/(?:&|(\?))' . $key . '=[^&]*(?(1)&|)?/i', "$1", $url);
}

//How to use
$url = "https://gist.github.com/?test=false";
$key = "test";
$newURL = removeQueryParam($url,$key);
//Output will be ==>  https://gist.github.com/