internal/rosa: pass stage alongside state

This cleans up many function signatures.

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

internal/rosa/zstd.go

@@ -2,12 +2,12 @@ package rosa
 
 import "hakurei.app/internal/pkg"
 
-func (t Toolchain) newZstd(s *S) (pkg.Artifact, string) {
+func (t Toolchain) newZstd() (pkg.Artifact, string) {
 	const (
 		version  = "1.5.7"
 		checksum = "4XhfR7DwVkwo1R-TmYDAJOcx9YXv9WSFhcFUe3hWEAMmdMLPhFaznCqYIA19_xxV"
 	)
-	return s.NewPackage(t, "zstd", version, newFromGitHubRelease(
+	return t.NewPackage("zstd", version, newFromGitHubRelease(
 		"facebook/zstd",
 		"v"+version,
 		"zstd-"+version+".tar.gz",