Fix import of py_io

[dcsynteny]

The current version of this import makes interrogate fail with an ImportError because there is no definition of "io" in py.py, with interrogate==1.5.0 and py==1.11.0:

ImportError: cannot import name 'io' from 'py' 

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Description

Motivation and Context

Have you tested this? If so, how?

Checklist for PR author(s)

• Changes are covered by unit tests (no major decrease in code coverage %).
• All tests pass.
• Docstring coverage is 100% via tox -e docs or interrogate -c pyproject.toml (I mean, we should set a good example 😄).
• Updates to documentation:
  • Document any relevant additions/changes in README.rst.
  • Manually update both the README.rst and docs/index.rst for any new/changed CLI flags.
  • Any changed/added classes/methods/functions have appropriate versionadded, versionchanged, or deprecated directives. Find the appropriate next version in the project's __init__.py file.

Release note