internal/rosa: replace busybox with toybox

The busybox artifact does not run on aarch64, and the workarounds required for it to compile successfully on x86_64 is unacceptably shaky. This change fully replaces it with toybox.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/rosa/hakurei.go

@@ -11,6 +11,8 @@ func (t Toolchain) newHakurei(script string) pkg.Artifact {
 	)
 	return t.New("hakurei-"+version, false, []pkg.Artifact{
 		t.Load(Go),
+
+		t.Load(Gzip),
 		t.Load(PkgConfig),
 
 		t.Load(KernelHeaders),