convert to podman

* call podman exec instead of using API:
  - build does not support progress
  - run looks like to lack equivalent dockerpty support
* config: use full uri as short names are not supported on
  all OSes (like debian 11)

setup.py

@@ -9,8 +9,6 @@ setup(
     packages = find_packages(),
     python_requires = ">=3.6",
     install_requires = [
-        "docker",
-        "dockerpty",
         "pathlib",
         "pyxdg",
         "pyyaml",