[Calcite] Make containsNestedAggregator tolerate flat-leaf schemas#5423

ahkcs merged 2 commits into

opensearch-project:feature/mustang-ppl-integrationopensearch-project/sql:feature/mustang-ppl-integrationfrom

mch2:feature/mustang-ppl-integrationmch2/sql:feature/mustang-ppl-integrationCopy head branch name to clipboard