Bump rmccue/requests 2.0.3

[StirStudios]

"require": {
    "rmccue/requests": "^1.7"
},

Any chance we can get a bump so this package is PHP8.1 compatible?

[StirStudios]

Forked and updated as needed:
https://github.com/StirStudios/Sendy-PHP-API

[zadro]

Bump to get the rmccue/requests package updated.

Bump.

   DEPRECATED  Return type of Requests_Cookie_Jar::offsetExists($key) should either be compatible with ArrayAccess::offsetExists(mixed $offset): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in vendor/rmccue/requests/library/Requests/Cookie/Jar.php on line 63.

Better would be to remove this dependency and rely on Guzzle instead.

@StirStudios Your fork throws an error for me. Looks like the composer.json also does not require the Symfony classes btw. Perhaps this would be best: https://symfony.com/doc/current/http_client.html

Call to undefined method Symfony\Component\HttpFoundation\Request::post() in API.php on line 356. Looks like the post method does not exist on the Request class.

[EDIT]
Swapped the HTTP lib for Guzzle: https://github.com/Fossil01/Sendy-PHP-API

#14