Update for Laravel 9 and PHP 8

[fosron]

Implement migration from Swift Mailer to Symfony Mailer for Laravel 9

laravel/framework#38481

Release as v2 branch to not introduce BC.

[IsraelOrtuno]

I guess this is a breaking change for the current version?

https://laravel.com/docs/9.x/upgrade#symfony-mailer

[fosron]

@IsraelOrtuno Yes, we will be updating and releasing a v2 for the driver soon.

[fosron]

There's a WIP version ready - composer require mailersend/laravel-driver:dev-v2-update-symfonymailer , though need to test a little bit more before releasing v2.