add test for groupBy not throwing tooManySubstreamsOpenException on closed substream#2742

pjfanning merged 2 commits intoapache:mainapache/pekko:mainfrom

pjfanning:copilot/port-akka-core-pull-31872pjfanning/incubator-pekko:copilot/port-akka-core-pull-31872Copy head branch name to clipboard