deps: Allow minor version updates of Ansible

It seems that minor updates of Ansible really are minor [1], so there's very little risk of breaking anything. Our current strict requirement makes it harder to package Enoslib in Nix.

As documented in [2], Enoslib users that care about reproducibility are encouraged to freeze all dependencies, including Ansible.

[1] https://github.com/ansible-community/ansible-build-data/blob/main/7/CHANGELOG-v7.rst [2] https://discovery.gitlabpages.inria.fr/enoslib/tutorials/reproducibility.html