feature: Use PSR-18 compatible wrapper for Laravel HTTP client

[dshafik]

I was trying to review OpenAI requests using Telescope which captures requests made using the Laravel HTTP Client, however this integration uses Guzzle directly.

The OpenAI PHP library supports any PSR-18 compatible client, so I pulled in swisnl/laravel-psr-http-client-bridge which is a PSR-18 compatible wrapper around the Laravel HTTP Client and used that instead of Guzzle directly.

This change allows the requests to show up in Telescope as expected.

[iBotPeaches]

I'm a bit nervous that we move our implementation to a 3rd party wrapper package. It seems my argument is more with Laravel on why their HTTP Client isn't PSR-18 compatible. When we saw the last implementation (https://github.com/gehrisandro/laravel-http-psr18) of wrapping Laravel/HTTP it had some issues.

I wonder what we are looking at in terms of stability. Is this package basically done forever, barring a major Guzzle change? It seems PSR-18 is set and Guzzle probably isn't changing until a major.