Bullet ray picking should ignore objects with input_ray_pickable=false

Created by: JPTeasdale

This is a fix for https://github.com/godotengine/godot/issues/21194

You can see in the code that if m_pickRay is true, gObj->is_ray_pickable() is false, and m_exclude->has(gObj->get_self()) is false then the function will return true which is not desired because gObj->is_ray_pickable() is false.

Testing notes: I recompiled the engine and ran the Picking Problem project posted in the task. All picks performed as expected.