feat: add support for Laravel 12

[z4nder]

What this PR does

This PR adds compatibility with Laravel 12 by updating the illuminate/support version constraint to allow ^12.0.

Why it's needed

Laravel 12 is officially released, and this package currently prevents installation due to strict version constraints.

Closes #24

[notcoderguy]

You can use @z4nder repo as package till this is merged:

Place the following inside your composer.json file:

"repositories": {
        "deepseek": {
            "type": "package",
            "package": {
                "name": "deepseek-php/deepseek-laravel",
                "version": "1.0",
                "source": {
                "url": "https://github.com/z4nder/deepseek-laravel.git",
                "type": "git",
                "reference": "origin/support-laravel-12"
                }
            }
        }
    },

After the following you can now use the following command to get the package from the repo directly:

composer require deepseek-php/deepseek-laravel

[z4nder]

You can use @z4nder repo as package till this is merged:

Thanks for the tip! This solution helps a lot while the PR is pending. Once it's merged, I'll switch back to the main package.

[epellox]

Looking great!