Update requirements.

[jefhar]

Update for L12.

The upstream Laravel Contracts requires PHP 8.3 as minimum version.

To use this package:

Temporarily add this fork to the repositories property of your composer.json:

{
    "repositories": [
        {
            "type": "vcs",
            "url": "https://github.com/jefhar/laravel-env-keys-checker.git"
        }
    ]
}

Then update your dependency constraint to reference this branch:

{
    "require": {
        "msamgan/laravel-env-keys-checker": "dev-l12-compatibility",
    }
}

Finally, run: composer update

[msamgan]

I am sorry, but at this time, I won't be able to merge the PR. If you have an issue with installation, please create a description in detail of what you faced with other relevant data.

This will make adding the package to the code unnecessarily hard. Hope you will understand.