gh-127264: Update document behavior of Path.resolve()

[wei-juncheng]

Closes #127264

What

Issue #127264 pointed out that users relying on exists() as a safe pre-check for resolve() may still encounter an unexpected FileNotFoundError when the cwd is gone. This note:

• Explains the underlying cause (the getcwd() call).
• Warns that non-strict mode isn’t immune to failing when the cwd is deleted.
• Reminds users that a pre-check with exists() can race with filesystem changes.

How

• Added a “.. note::” under the “Expanding and resolving paths” section of Doc/library/pathlib.rst to document that Path.resolve(strict=False) will call os.getcwd() internally and thus can raise FileNotFoundError if the current working directory has been deleted.

• Issue: pathlib: Path('.').exists() returns True when current working directory (cwd) was deleted #127264

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📚 Documentation preview 📚: https://cpython-previews--135531.org.readthedocs.build/

[python-cla-bot]

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[uranusjr]

Should we also add this to os.path.realpath documentation?

[github-actions]

This PR is stale because it has been open for 30 days with no activity.