wayland: Remove now removed CLUTTER_AVAILABLE_ API annotations
wayland: Remove now removed CLUTTER_AVAILABLE_ API annotations

In 00bee5f the API annotations were removed as the API is refreshed from
the start. This change removes the annotations from the Wayland API.

https://bugzilla.gnome.org/show_bug.cgi?id=703202

collects/clutter,jigpu/clutter,jigpu/clutter,collects/clutter,ebassi/clutter,collects/clutter,heysion/clutter-clone,Distrotech/clutter,collects/clutter,GNOME/clutter,jigpu/clutter,Distrotech/clutter,GNOME/clutter,Distrotech/clutter,ebassi/clutter,Distrotech/clutter,ebassi/clutter,heysion/clutter-clone,djdeath/clutter,heysion/clutter-clone,jigpu/clutter,heysion/clutter-clone,GNOME/clutter,heysion/clutter-clone,djdeath/clutter,Distrotech/clutter,djdeath/clutter,djdeath/clutter,jigpu/clutter,ebassi/clutter,djdeath/clutter,Distrotech/clutter,jigpu/clutter,GNOME/clutter,GNOME/clutter,djdeath/clutter,ebassi/clutter,collects/clutter