Corrected information that Sensor.is_listening is (currently) a method

[Daraan]

Description

carla.Sensor.is_listening is defined twice (since #6013) the <0.9.14 property is overwritten with a method; can also be seen in the Docs

This PR removes the overwritten property and updates the doc, keeping the 0.9.14+ method version in tact.

carla/PythonAPI/carla/source/libcarla/Sensor.cpp

Lines 29 to 31 in f22d49d

	.add_property("is_listening", &cc::Sensor::IsListening)
	.def("listen", &SubscribeToStream, (arg("callback")))
	.def("is_listening", &cc::Sensor::IsListening)

Where has this been tested?

• Platform(s): Ubuntu 22.04
• Python version(s): 3.7 and 3.10
• Unreal Engine version(s): 4.26
• all checks green

Possible Drawbacks

None.

Future work, make it a property again?

I at least would prefer function names like is_listening as a property. On one side, it would break the current 0.9.14/15 compatibility, on the other it would restore the one from <0.9.13 which still is found in code more often.
So we might want to shift the three Sensor.is_... functions to a property.

[update-docs]

Thanks for opening this pull request! The maintainers of this repository would appreciate it if you would update our CHANGELOG.md based on your changes.