Upgrade PHPstan & Larastan

[peterfox]

Changes

• Replaces Larastan for the correct version
• Allows for the installation of PHPStan 2.0
• Updates the PHPStan config for a new version

Why

A small bit of maintenance and clean-up. Happy New Year!

[ash-jc-allen]

Hey @peterfox, thanks for this PR! 😄

Just a quick question: Is there any benefit to adding phpstan/phpstan as a direct dependency in the composer.json? I would have guessed the correct version would be installed as a dependency of Larastan. But I might have missed something though haha 🙂

[peterfox]

@ash-jc-allen a good question! Normally you'd be right. I found when I pushed this originally to check it against the GH actions, it failed due to the config change in this PR. Older PHPStan 1.0 versions won't use the new config change.

I'd add it to the project purely to make sure the PHPStan version installed is compatible with the config. Being a dev dependency, it won't affect anyone using the package but make life for anyone developing.

[ash-jc-allen]

Ahh yeah, that makes sense, thanks! In all fairness, I've been meaning to drop support for Laravel 8 for a while since it's not been updated for quite a while. So I've taken this as a chance to drop it (in PR #164) so we can keep this change nice and simple! 😄

Thanks again for this contribution. I'll get it bundled up now into a release 🎉