libuv: drop a test that seems flaky on Hydra

https://hydra.nixos.org/log/lg744sdh93maxbb68bk1p29a9rpnx2pw-libuv-1.44.1.drv

+1
+1
pkgs/development/libraries/libuv/default.nix
··· 20 20 "threadpool_multiple_event_loops" # times out on slow machines 21 21 "get_passwd" # passed on NixOS but failed on other Linuxes 22 22 "tcp_writealot" "udp_multicast_join" "udp_multicast_join6" # times out sometimes 23 + "fs_fstat" # https://github.com/libuv/libuv/issues/2235#issuecomment-1012086927 23 24 ] ++ lib.optionals stdenv.isDarwin [ 24 25 # Sometimes: timeout (no output), failed uv_listen. Someone 25 26 # should report these failures to libuv team. There tests should