internal/rosa: stage3 special case helper

This makes it cleaner to specify non-stage3 and stage3-exclusive dependencies.

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

internal/rosa/cmake.go

@@ -81,14 +81,6 @@ func (t Toolchain) NewViaCMake(
 		panic("CACHE must be non-empty")
 	}
 
-	cmakeExtras := []pkg.Artifact{
-		t.NewCMake(),
-		t.NewNinja(),
-	}
-	if t == toolchainStage3 {
-		cmakeExtras = nil
-	}
-
 	scriptEarly := attr.ScriptEarly
 	if attr.Writable {
 		scriptEarly = `
@@ -102,9 +94,9 @@ chmod -R +w "${ROSA_SOURCE}"
 	}
 
 	sourcePath := AbsUsrSrc.Append(name)
-	return t.New(name+"-"+variant+"-"+version, slices.Concat(
-		attr.Extra,
-		cmakeExtras,
+	return t.New(name+"-"+variant+"-"+version, stage3Concat(t, attr.Extra,
+		t.NewCMake(),
+		t.NewNinja(),
 	), nil, slices.Concat([]string{
 		"ROSA_SOURCE=" + sourcePath.String(),
 		"ROSA_CMAKE_SOURCE=" + sourcePath.Append(attr.Append...).String(),