fix: bazzite should be detected as FedoraImmutable

[SteveLauC]

What does this PR do

As titled, closes #1033

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[dtomvan]

In src/steps/os/linux.rs:65:

               match variant {
                   "Silverblue" | "Kinoite" | "Sericea" | "Onyx" | "IoT Edition" | "Sway Atomic" => {

Shouldn't VARIANT="Kinoite" inside of /etc/os-release already get detected without this PR?

Anyways, LGTM, but it could be useful to add cases for Aurora, Bluefin and uCore as well?

[dtomvan]

Correction:

Shouldn't VARIANT="Kinoite" inside of /etc/os-release already get detected without this PR?

They don't get picked up because they are behind a ID=fedora check, but on bazzite this is ID=bazzite. I'll try to fix the problem.

[dtomvan]

All right, decided to refactor it a bit because I am dealing with this issue too. Could you review my PR #1043? I included this commit too.

[SteveLauC]

Close as this has been superseded by #1043