test/dns: mark TCP tests as retriable CI: https://github.com/azat/libevent/runs/3643912296 # tcp_resolve_many_clients CI: https://github.com/azat/libevent/runs/3643912192 # tcp_timeout CI: https://github.com/azat/libevent/runs/3643912336 # tcp_resolve CI: https://github.com/azat/libevent/runs/3643912174 # tcp_resolve_pipeline