2.x - Drop support for PHP <= 8.1

[Sweetchuck]

A little refactor.

A new branch is needed to create a pull request.
https://github.com/Sweetchuck/mindscreen-yarnlock/tree/2.x

[PRGfx]

Thank you for your work. You suggest a "2.x" branch (as new default branch)? I would wait for #5 with that and create it off that.

I will look through your changes if there is a PR then, but can you maybe outline how (much) this is breaking existing interfaces?
As PHP < 8.1 is EOL, I don't see additional 1.x changes, i.e. I would just tag the releases and continue with 2.x. For now I'm not yet convinced to maintain separate branches – if need be I guess we could branch off of a 1.x tag..

[PRGfx]

I tagged the presumably last 1.x release and created a 2.x branch.