[ROS2] Add env-hook with ament_python built package to use Gazebo model with meshes

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I'm working with ament_python built ROS2 foxy package for gazebo simulation. I have several SDF models using various meshes (.dae) files (with parts like: <mesh><uri>model://my_model/meshes/something.dae</uri>/mesh>* ). I followed the ROS 2 Migration: Gazebo ROS Paths guide and the only thing that I'm missing (hopefully) is to add environment hooks as it is written here to my CMakeList file which I don't have. How can I do that with the only python? (or if its not needed for my goal what should I do?)