ycb_django_pr11603

what a new run launched now would send

Add DISTINCT support for Avg and Sum aggregates.
Description
	
As an extension of #28658, aggregates should be supported for other general aggregates such as Avg and Sum. Before 2.2, these aggregations just ignored the parameter, but now throw an exception.
This change would just involve setting these classes as allowing DISTINCT, and could also be applied to Min and Max (although pointless).

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