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.

source/blender/makesrna/SConscript

@@ -47,6 +47,10 @@ defs = []
 if env['WITH_BF_SMOKE']:
     defs.append('WITH_SMOKE')
 
+if env['WITH_BF_BULLET']:
+    defs.append('WITH_BULLET')
+    incs += ' ../../rigidbody'
+
 if env['WITH_BF_OPENEXR']:
     defs.append('WITH_OPENEXR')