`ECONNRESET` in `test_io_cohttp` on freebsd with OCaml 4.14

[polytypic]

I noticed this happening on the CI:

138 |  (name test_io_cohttp)
^^^^^^^^^^^^^^
(cd _build/default/test && ./test_io_cohttp.exe)
Fatal error: exception Unix.Unix_error(Unix.ECONNRESET, "close", "")
Raised by primitive operation at Picos_std_finally.forbidden in file "lib/picos_std.finally/picos_std_finally.ml", line 40, characters 14-23
Re-raised at Picos_std_finally.forbidden in file "lib/picos_std.finally/picos_std_finally.ml", line 44, characters 12-21
Called from Picos_std_finally.release_and_return in file "lib/picos_std.finally/picos_std_finally.ml", line 60, characters 2-21
Called from Dune__exe__Test_io_cohttp.main.(fun) in file "test/test_io_cohttp.ml", line 54, characters 10-96
Called from Picos_std_structured__Bundle.join_after_realloc in file "lib/picos_std.structured/bundle.ml", line 98, characters 8-12
Re-raised at Picos_std_structured__Control.Errors.check in file "lib/picos_std.structured/control.ml", line 41, characters 23-59
Called from Picos_std_structured__Bundle.await in file "lib/picos_std.structured/bundle.ml", line 76, characters 2-31
Called from Picos_std_structured__Bundle.raised in file "lib/picos_std.structured/bundle.ml", line 82, characters 2-37
Called from Picos_std_finally.finally in file "lib/picos_std.finally/picos_std_finally.ml", line 184, characters 8-15
Re-raised at Picos_std_finally.release_and_reraise in file "lib/picos_std.finally/picos_std_finally.ml", line 57, characters 2-38
Called from Picos.Bootstrap.Computation.capture in file "lib/picos/picos.ocaml5.ml", line 348, characters 11-15
Re-raised at Picos.Bootstrap.Computation.raise in file "lib/picos/picos.ocaml5.ml", line 354, characters 4-40
Called from Dune__exe__Test_io_cohttp in file "test/test_io_cohttp.ml", line 66, characters 9-47