feat: Add support for Wolfi

[EyeCantCU]

This adds support for updating Wolfi via Topgrade

Standards checklist:

• The PR title is descriptive.
• I have read CONTRIBUTING.md
• The code compiles (cargo build)
• The code passes rustfmt (cargo fmt)
• The code passes clippy (cargo clippy)
• The code passes tests (cargo test)
• Optional: I have tested the code myself

[SteveLauC]

Hi, thanks for contributing to Topgrade, changes LGTM, though I recommend adding

1. its /etc/os-release file
2. A unit test on the parsing procedure

BTW, I am collecting Linux distros' os-release file here, would you like to add Wolfi's one to the repo? Much appreciated if you are willing to do it:)

[EyeCantCU]

Thanks for the review! I can certainly make those changes here shortly

[SteveLauC]

Thanks! And congratulations on your first contribution to Topgrade!