Is your feature request related to a problem or challenge?

Currently, AggregateExec does not implement gather_filters_for_pushdown, which means
dynamic filters cannot pass through aggregations.

In most cases this is correct behavior - when aggregate functions like SUM(),
COUNT(), AVG() are used, filtering rows before aggregation would produce incorrect
results.

However, there's an important special case: pure grouping operations (DISTINCT
or GROUP BY without aggregate functions). For these operations, it's safe to push
filters through because they only de-duplicate data without computing new values. This blocks significant optimization opportunities for queries with DISTINCT or pure
GROUP BY on the probe side of inner joins i think

Describe the solution you'd like

No response

Describe alternatives you've considered

No response

Additional context

No response