Adds the correct way of setting filters

[dulte]

Fixed the problem we discussed with the filters

[heikoklein]

Some tests should maybe changed, too, i.e. change https://github.com/metno/pyaro-readers/blob/22ca00ae1bc564a927b9fc757d31c44ffca355ad/tests/test_AERONETSDATimeSeriesReader.py#L119C9-L121C73

sfilter = pyaro.timeseries.filters.get("stations", exclude=["Cuiaba"])
        with engine.open(
            self.file, filters=[sfilter], tqdm_desc="test_stationfilter"

to

        with engine.open(
            self.file, filters={"stations": {"exclude": ["Cuiaba"]}}, tqdm_desc="test_stationfilter"

[jgriesfeller]

Thanks for taking this. All good.