internal/rosa: remove busybox artifact

This is no longer used and its implementation is unacceptably shaky.

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

internal/rosa/all.go

@@ -14,7 +14,6 @@ const (
 	Attr
 	Autoconf
 	Bash
-	Busybox
 	CMake
 	Coreutils
 	Diffutils
@@ -94,7 +93,6 @@ func ResolveName(name string) (p PArtifact, ok bool) {
 		"attr":              Attr,
 		"autoconf":          Autoconf,
 		"bash":              Bash,
-		"busybox":           Busybox,
 		"cmake":             CMake,
 		"coreutils":         Coreutils,
 		"diffutils":         Diffutils,