ocamlPackages.pa_ounit: 112.24.00 -> 113.00.00

Semi-automatic update generated by https://github.com/ryantm/nix-update tools. These checks were done:

- built on NixOS
- Warning: no binary found that responded to help or version flags. (This warning appears even if the package isn't expected to have binaries.)
- found 113.00.00 with grep in /nix/store/rpbwnyaisfm27cf36hb7scsa833r1lkb-ocaml-pa_ounit-113.00.00
- directory tree listing: https://gist.github.com/7284ca806fd00f73984a14b088879e92