New packages: unison2.48+4.04.2, unison2.48+4.08.1

[Andrew Schulman]

Please add me as the maintainer for two new Unison packages:

unison2.48+4.04.2
unison2.48+4.08.1

If you want to know why we need this, please see the thread starting at [1]
(and continuing at [2], thanks pipermail). I'm going to release them
initially as test packages, to see if they have the right OCaml versions to
meet the current need. There may be more in the future.

Thanks,
Andrew

[1] https://cygwin.com/pipermail/cygwin/2020-August/246097.html
[2] https://cygwin.com/pipermail/cygwin/2020-September/246099.html