introspection: Remove 'caller-allocates' from POD types
requested to merge ptomato/gobject-introspection:remove-out-caller-allocates-from-pod-types into master
The (out caller-allocates) and (out callee-allocates) annotations are meant for structured or pointer types. Plain old data types are just regular out parameters and don't need the annotation about who allocates them.
See: glib!2005 (merged)