Replace pipes.quote for Python 3.13 compatibility

[Mirochill]

Summary

• use shlex.quote on current Python versions so importing the wrapper no longer depends on pipes, which was removed in Python 3.13
• retain a conditional pipes.quote fallback for Python 2.7, which is still listed in the package classifiers

Notes

• PR added support for PurePath objects for defining source file. #24 modifies the same quoting call for pathlib.Path support, but retains pipes.quote; it may need rebasing if both changes are pursued

Validation

• git diff --check HEAD~1..HEAD
• Not run locally

Refs #26