https://github.com/TerryHowe/ansible-modules-hashivault/pull/467 breaks installs that use pip based hvac

[nyetwurk]

#467 breaks installs that require pip to install hvac.

There is no alpine py3-hvac so hardcoding shebang breaks python venv setups

[TerryHowe]

Fix one thing, break another. This was the Ansible recommended shebang outlined in a link near the bottom of #412