Merged NRRPLT-8358-hide-ant-experiment into development

[NRRPLT-8358] Set pybullet_ant maturity to development, remove it from public robots; it's incompatible with gazebo version > 9.8

pybullet_ant/model.config

@@ -4,7 +4,7 @@
        xsi:schemaLocation="http://schemas.humanbrainproject.eu/SP10/2017/robot_model_config ../robot_model_configuration.xsd">
   <name>PyBullet Ant</name>
   <version>1.0</version>
-  <maturity>production</maturity>
+  <maturity>development</maturity>
   <thumbnail>thumbnail.png</thumbnail>
   <license>MIT</license>
   <sdf version="1.6">model.sdf</sdf>

robots/pybullet_ant

-../pybullet_ant
\ No newline at end of file