Lone_Wolf [1] filed a deletion request for openscenegraph34 [2]:
Openmw in repos now works fine with latest openscenegraph again, this
package is no longer needed.
I have no idea why flightgear-git and simgear-git
depend on this, but they haven't been tested with this package.
[1] https://aur.archlinux.org/account/Lone_Wolf/
[2] https://aur.archlinux.org/pkgbase/openscenegraph34/