Add podman connector

[Griffoen]

The Podman CLI is compatible with the Docker CLI, so I refactored the docker connector to create the Podman connector.
This enables users of distros which prefer Podman over Docker to test their deployments more easily.

The Podman connector works exactly like the docker connector, for example: pyinfra @podman/fedora:42 dnf packages=uv

I copied the docker tests in /tests/test_connectors/test_docker.py for the Podman tests.
However, I omitted the /test/end-to-end/test_e2e_docker.py tests since I don't know how they are supposed to be set up, and I don't have docker installed to run the tests.

[Griffoen]

The failing test (below) has nothing to do with this MR, and it succeeded after a re-run while developing this MR.
I don't know what is going on here, but it does not affect this MR as far as I can tell.

=========================== short test summary info ============================
FAILED tests/test_connectors/test_ssh.py::TestSSHConnector::test_get_file_sudo - AssertionError: expected call not found.
Expected: getfo('/tmp/pyinfra-e9c0d3c8ffca943daa0e75511b0a09c84b59c508', <MagicMock name='open()' id='139776354182096'>)
  Actual: not called.
========== 1 failed, 1169 passed, 12 deselected, 1 warning in 22.55s ===========