Fix http_build_query in OTP class (#215)

The change fixes a syntax issue with http_build_query in OTP class. Specifically, incorrect usage of 'arg_separator' as a keyword argument results in an error. Replaced that incorrect usage with the appropriate way of using this function, improving the reliability and correctness of building the query string.

src/OTP.php

@@ -100,7 +100,7 @@ protected function generateURI(string $type, array $options): string
         $this->hasColon($label) === false || throw new InvalidArgumentException('Label must not contain a colon.');
         $options = [...$options, ...$this->getParameters()];
         $this->filterOptions($options);
-        $params = str_replace(['+', '%7E'], ['%20', '~'], http_build_query($options, arg_separator: '&'));
+        $params = str_replace(['+', '%7E'], ['%20', '~'], http_build_query($options, '', '&'));
 
         return sprintf(
             'otpauth://%s/%s?%s',