internal/rosa: lazy initialise all artifacts

This improves performance, though not as drastically as lazy initialising llvm.

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

internal/rosa/go.go

@@ -10,7 +10,7 @@ import (
 func (t Toolchain) newGoBootstrap() pkg.Artifact {
 	const checksum = "8o9JL_ToiQKadCTb04nvBDkp8O1xiWOolAxVEqaTGodieNe4lOFEjlOxN3bwwe23"
 	return t.New("go1.4-bootstrap", []pkg.Artifact{
-		t.NewBash(),
+		t.Load(Bash),
 	}, nil, []string{
 		"CGO_ENABLED=0",
 	}, `
@@ -65,8 +65,7 @@ sh make.bash
 	)))
 }
 
-// NewGo returns a [pkg.Artifact] containing the Go toolchain.
-func (t Toolchain) NewGo() pkg.Artifact {
+func (t Toolchain) newGoLatest() pkg.Artifact {
 	go119 := t.newGo(
 		"1.19",
 		"9_e0aFHsIkVxWVGsp9T2RvvjOc3p4n9o9S8tkNe9Cvgzk_zI2FhRQB7ioQkeAAro",
@@ -90,3 +89,4 @@ func (t Toolchain) NewGo() pkg.Artifact {
 	)
 	return go125
 }
+func init() { artifactsF[Go] = Toolchain.newGoLatest }