GHSA-2WPX-QPW2-G5H5 CoreDNS' DoQ worker pool does not bound stream backlog

Summary CoreDNS' DNS-over-QUIC DoQ server can be driven into large goroutine and memory growth by a remote client that opens many QUIC streams and stalls after sending only 1 byte. Even with a small configured quic workerpoolsize ... , CoreDNS still spawns a goroutine per accepted stream workers ...