fix common-data pack reference for newly places demos

apps/demos/platformer/data/packs/data.toml

@@ -1,3 +1,3 @@
 [[deps]]
-source = "../../common-data" # where does it come from, might be an url
+source = "../../../common-data" # where does it come from, might be an url
 name = "common-data"         # should be globally unique