audio: Ignore `ignore-inactive-pads` property in `AudioAggregator`
requested to merge slomo/gstreamer-rs:audioaggregator-ignore-ignore-inactive-pads-property into main
getters/setters are already generated for the Aggregator base class
and the property in the subclass is not really needed here. It also
causes problems with trait resolution as the getter/setter functions
will exist twice.