Add py_trees_ros_tutorials repo to ros2-gbp

[sea-bass]

In #44155 (and its Jazzy/Humble counterparts), I indexed two packages: py_trees_ros_viewer and py_trees_ros_tutorials.

However, looking at the ros2-gbp org, there does not seem to be a py_trees_ros_tutorials-release repo (though the other one did already exist). Meaning I can't bloom this.
https://github.com/ros2-gbp?q=py_trees&type=all&language=&sort=

Is this something the maintainers can help with? Unsure of how this goes for new packages. Thanks!

[sea-bass]

ah, I see where to do it now. Closing this.