stdlib: simpler and cleaner performance workaround

Signed-off-by: Solomon Hykes <solomon@dagger.io>

stdlib/dagger/dagger.cue

@@ -1,14 +1,17 @@
 package dagger
 
 import (
+	"dagger.io/dagger/op"
 )
-// "dagger.io/dagger/op"
 
 // An artifact such as source code checkout, container image, binary archive...
 // May be passed as user input, or computed by a buildkit pipeline
 
-// FIXME (perf). See https://github.com/dagger/dagger/issues/445
-#Artifact: _
+#Artifact: {
+	#up: [...op.#Op]
+	_
+	...
+}
 
 // Secret value
 // FIXME: currently aliased as a string to mark secrets