Add private APIs to get Python version before bootstrapping Python. ### Description

Add private APIs (module.\_py_version_{major,minor,micro}) to get the Python version before bootstrapping Python, and use it in Module.preRun to initialize filesystem.

### Checklists

- [x] Add / update tests

package:
  name: tskit
  version: 0.5.3
  top-level:
    - tskit
source:
  url: https://files.pythonhosted.org/packages/72/78/ff5bcd512f2a2f1ea253da96fb824cd20dc3f60513b03619f37487cc2eca/tskit-0.5.3.tar.gz
  sha256: 1dc6f10bd805b757bcce4bb2dc81b7dcda5379af019928222663f3d8ace3e997
requirements:
  run:
    - numpy
    - svgwrite
    - jsonschema
about:
  home: https://tskit.dev/tskit
  PyPI: https://pypi.org/project/tskit
  summary: The tree sequence toolkit.
  license: MIT

package:
  name: tskit
  version: 0.5.3
  top-level:
    - tskit
source:
  url: https://files.pythonhosted.org/packages/72/78/ff5bcd512f2a2f1ea253da96fb824cd20dc3f60513b03619f37487cc2eca/tskit-0.5.3.tar.gz
  sha256: 1dc6f10bd805b757bcce4bb2dc81b7dcda5379af019928222663f3d8ace3e997
requirements:
  run:
    - numpy
    - svgwrite
    - jsonschema
about:
  home: https://tskit.dev/tskit
  PyPI: https://pypi.org/project/tskit
  summary: The tree sequence toolkit.
  license: MIT
