Upgrade pylint (#27279)

* Upgrade pylint to 2.4.2 and astroid to 2.3.1

https://pylint.readthedocs.io/en/latest/whatsnew/2.4.html
https://pylint.readthedocs.io/en/latest/whatsnew/changelog.html#what-s-new-in-pylint-2-4-1
https://pylint.readthedocs.io/en/latest/whatsnew/changelog.html#what-s-new-in-pylint-2-4-2

* unnecessary-comprehension fixes

* invalid-name fixes

* self-assigning-variable fixes

* Re-enable not-an-iterable

* used-before-assignment fix

* invalid-overridden-method fixes

* undefined-variable __class__ workarounds

https://github.com/PyCQA/pylint/issues/3090

* no-member false positive disabling

* Remove some no longer needed disables

* using-constant-test fix

* Disable import-outside-toplevel for now

* Disable some apparent no-value-for-parameter false positives

* invalid-overridden-method false positive disables

https://github.com/PyCQA/pylint/issues/3150

* Fix unintentional Entity.force_update override in AfterShipSensor

homeassistant/components/upnp/sensor.py

@@ -164,7 +164,6 @@ class PerSecondUPnPIGDSensor(UpnpSensor):
         """Get unit we are measuring in."""
         raise NotImplementedError()
 
-    @property
     def _async_fetch_value(self):
         """Fetch a value from the IGD."""
         raise NotImplementedError()