Update galaxy-importer PyYAML required version

Problem Description: Update galaxy-importer to be less restrictive to allow installation of PyYAML 6.x.x releases to increase compatibility with other CI tooling such as Molecule:

https://github.com/ansible-community/molecule/blob/6ae8c01fd426f20bfd0f181d73284eb7816c03c3/requirements.txt#L75

Proposed Solution:

update requirement as follow: `pyyaml>=5.4.1,<7` or `pyyaml==6.0.0`

https://github.com/ansible/galaxy-importer/blob/eb5ead417c703363beb04d082eb3b2a0767af6fb/setup.cfg#L28

I successfully executed galaxy-importer locally with the arista.avd collection and PyYAML 6.0.0.