text: Title: [Search][Expressions] Remove `AbortController` polyfill 
  Body: Kibana's node version is at 16 now so we can remove `AbortController` polyfills: 
  
  https://github.com/elastic/kibana/blob/66aca8b486342727de3f5c95821bbeb22fae3d29/src/plugins/data/server/lib/get_request_aborted_signal.ts#L11
  
  https://github.com/elastic/kibana/blob/66aca8b486342727de3f5c95821bbeb22fae3d29/src/plugins/expressions/common/execution/execution.ts#L79