upgrade `ipaclient` and unpin packages

https://github.com/coldfront/coldfront/pull/893

as soon as [this commit](https://github.com/freeipa/freeipa/commit/d4d56a6705c870901bc73882e4804367f7c9c91a) is released, we can upgrade `ipaclient` to that version and then unpin `setuptools`, `cryptography`