Migrate all daily aggregated events to weekly once

Problem

We know that the aggregation attribute for known_events.yml is superfluous and no longer needed (see #387785 (comment 1235366082)).

Before removing aggregation property we need to migrate all daily events to weekly aggregation (default value).

Suggested Solution

Important: Our assumption currently is that a migration from daily to aggregation has no impact on the actual numbers being reported since we only allow up to weekly granularity when it comes to RedisHLL metrics anyway. This issue should also verify that this is actually the case and the change in aggregation does not have any impact on the actual metrics but is just technical in nature.