v2.9.0
tests: add positive test for reusing ambivalent filesystem
tests/kola: move blackbox tests to its own dir
*: fix errcheck warnings
internal: update for new experimental spec
tests: Initial positive/negative tests
tests/stubs: Add blackbox testing stub for userdel and groupdel
*: fix gosimple warnings
internal/exec/engine: write empty cache config when not provided
stages/disks: warn if libblkid finds multiple filesystem signatures