[3.12] community/py3-pygit2: update dependencies
six is no longer required; and a new dependency is necessary.
We are currently working on getting Alpine Linux 3.21 out. This means that merge requests that are not aimed to help with that (only affecting testing, new aports) have a lower priority at the moment. Please be patient, they will be eventually picked up.
six is no longer required; and a new dependency is necessary.