build: Add dependency on robot_properties_fingers

robot_properties_fingers is no published on PyPI so we can depend on it
in the pure-Python way.

Need at least version 2.0.2 as in the previous releases the URDF files
where not included.

setup.cfg

@@ -36,6 +36,7 @@ install_requires =
     gym >=0.23.1
     opencv-python >=4.2.0.34
     pyyaml >=5.3.1
+    robot_properties_fingers>=2.0.2
 
 scripts =
     demos/demo_cameras.py