ci: run KVM jobs on GitHub runners

[mkroening]

This allows running the Uhyve CI without requiring self-hosted runners.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 76.47%. Comparing base (ab4fb58) to head (dabf183).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #748      +/-   ##
==========================================
- Coverage   76.64%   76.47%   -0.17%     
==========================================
  Files          28       28              
  Lines        3609     3609              
==========================================
- Hits         2766     2760       -6     
- Misses        843      849       +6     

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[jounathaen]

So we had an internal discussion, and came to the conclusion that a switch only provides minor benefits at the moment and keeping a little independence with our infrastructure is a value on its own.

But we keep the PR open, so we can easily adapt if the need for the GH runners occurs.