scons: Add missing WITH_BULLET define

Fixes [#33980] Ridid Body crashes when changing Collision shape with playback
as well as several other rigid body bugs wtih scons.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@54092 954f8c5b-7b00-dc11-b283-0030488c597c