Support laravel 11

[Naoray]

What's changed

• dropped support for PHP < 8.1
• upgraded Carbon dep to v3
  • wrapped ->diffIn*() calls in abs() because they can now return negative values
• moved lang folder to root
• migrated phpunit.xml.dist to latest version
• removed registering MollieServiceProvider within CashierServiceProvider as this is already done in https://github.com/mollie/laravel-mollie
• restructured CashierServiceProvider
• replaced references to Mollie\Laravel\MollieApiWrapper with Mollie\Api\MollieApiClient
• removed usage of global mollie() helper method
• update github workflow test to include php 8.3 & Laravel v11 and drop php v8.0

[sandervanhooft]

1 non-blocking comment, feel free to release at your convenience

🔥

[dwaynehertroys]

Can this be merged?