PIPE-3073: Silence noisy Dask TCP probe and post-session log floods
* daskhelpers: add `_silence_stray_tcp_probe_logs()` to drop tornado/
distributed ERROR records produced when non-Dask clients (HTTP probes,
health checks, stale browser tabs) hit the scheduler port and trigger
bogus multi-EiB frame reads. Filter is targeted -- only matches the
stray-probe signature (`_handle_stream`, `BaseTCPListener`, our
"Implausible allocation request" marker, or MemoryError exc_info) so
gen
