Fixing PHP versions of Actions CI in Laravel 6 and 7.

[tobigumo]

Description of the change

Laravel 6 and 7 requires PHP 7.2 - 8.0, so exclude all PHP versions after 8.1 on GitHub Actions CI.
https://laravel.com/docs/master/releases#support-policy

Seeing #129 CIs failing, I created it as another PR.

Type of change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Maintenance
• New release

Related issues

Shortcut stories and GitHub issues (delete irrelevant)

Checklists

Development

• Lint rules pass locally
• The code changed/added as part of this pull request has been covered with tests
• All tests related to the changed code pass in development

Code review

• This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• "Ready for review" label attached to the PR and reviewers assigned
• Issue from task tracker has a link to this pull request
• Changes have been reviewed by at least one other engineer

[danielmorell]

Thank you @tobigumo for that link, and the PR. I was looking at the composer.json file yesterday for both v6 and v7. The PHP requirement includes PHP 8.1. However, it was clear that they have issues when trying to run on PHP 8.1.