internal/rosa/make: migrate to helper interface

This also updates all affected artifacts to use new behaviour.

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

internal/rosa/libxml2.go

@@ -11,21 +11,16 @@ func (t Toolchain) newLibxml2() pkg.Artifact {
 		version  = "2.15.1"
 		checksum = "pYzAR3cNrEHezhEMirgiq7jbboLzwMj5GD7SQp0jhSIMdgoU4G9oU9Gxun3zzUIU"
 	)
-	return t.NewViaMake("libxml2", version, pkg.NewHTTPGet(
+	return t.NewPackage("libxml2", version, pkg.NewHTTPGet(
 		nil, "https://download.gnome.org/sources/libxml2/"+
 			strings.Join(strings.Split(version, ".")[:2], ".")+
 			"/libxml2-"+version+".tar.xz",
 		mustDecode(checksum),
-	), &MakeAttr{
-		ScriptEarly: `
-cd /usr/src/
-tar xf libxml2.tar.xz
-mv libxml2-` + version + ` libxml2
-`,
-		SourceSuffix: ".tar.xz",
-	},
-		t.Load(Diffutils),
-		t.Load(XZ),
+	), &PackageAttr{
+		SourceKind: sourceTarXZ,
+	}, (*MakeHelper)(nil),
+		Diffutils,
+		XZ,
 	)
 }
 func init() { artifactsF[Libxml2] = Toolchain.newLibxml2 }