PHP 8 Support

[mruz]

Problem 3
- Installation request for imliam/laravel-env-set-command v1.2.0 -> satisfiable by imliam/laravel-env-set-command[v1.2.0].
- imliam/laravel-env-set-command v1.2.0 requires php ^7.3 -> your PHP version (8.0.0) does not satisfy that requirement.

laravel-env-set-command/composer.json

Line 23 in 7e41113

"php": "^7.3",