[8.x] ESQL: Fail in AggregateFunction when `LogicPlan` is not an `Aggregate`#125400

ivancea merged 2 commits intoelastic:8.xelastic/elasticsearch:8.xfrom

ivancea:backport-8.x-agg-verificationivancea/elasticsearch:backport-8.x-agg-verificationCopy head branch name to clipboard