Upgrade Symfony dependencies to v7

[hugopeek]

What does it do ?

Upgrade Symfony requirements to version 7 and make sure all commands are compatible.

This also fixes an issue I had where the build --force command was no longer working.

Why is it needed ?

I still don't fully understand how all this Composer machinery operates, but I am running into more and more compatibility issues (not just with Gitify). For some reason, Gitify is using a higher version (v6 or v7) of Symfony console sometimes, if autoloaded by another extra. These versions contain breaking changes, leading to fatal errors for some commands.

This is from an extract after adding a Composer package to an extra, which depends on Symfony 7 stuff. The error messages reference the foreign vendor folder:

Uncaught Error: Undefined constant Symfony\Component\Yaml\Yaml::DUMP_NULL_AS_EMPTY in /var/www/romanesco/backyard/core/components/romanescobackyard/vendor/symfony/yaml/Dumper.php:45

I suppose I could try to make Gitify stick to its own autoloader, but that feels a bit hacky. It probably makes more sense to adjust the commands so they become compatible with the higher Symfony versions. Or am I missing something, and is it pinned on Symfony 5 for a reason?

Anyway, I hope this will help for anyone else experiencing similar issues..