Update to PHP 8 and Symfony 7

[leofeyer]

Is it a good idea to commit the composer.lock file? The PHP version is now locked to 8.3 (my local version), even though the minimum requirement is only PHP 8.1.

[Toflar]

Just a minor nitpick now that we have new features available :)

[Toflar]

Is it a good idea to commit the composer.lock file? The PHP version is now locked to 8.3 (my local version), even though the minimum requirement is only PHP 8.1.

Of course it's good. It's an app :) We can hardcode the requirement in platform.config if you want that. But imho we can also adjust the require to ^8.3.