swatchbooker: fix little-cms dependency.
python_dependency: cleanup, fix satisfy.

Closes #26067.
opam: Capture required libs as resources.

Despite `md5` being deprecated in favor of `sha1`, I use `md5` because
the [`opam` Makefile uses MD5s][0], and it seems prudent to use its
reasoning.

[0]: https://github.com/ocaml/opam/blob/master/src_ext/Makefile#L3-19
opam: Adhere to zsh naming convention.
opam: Initialize the package DB in `post_install`

(rather than asking the user to do it)