bug#49171: [bug#49183] [PATCH] gnu: ocaml-dose3: Fix tests.

[pukkamustard]

Neat. Thanks!

Fixes the test and looks got to me.

No idea why one would use Python to test OCaml code...

Yeah, makes one wonder. At least they've updated to Python3 
(https://gitlab.com/irill/dose3/-/blob/master/CHANGES#L33) 
recently.