gh-138722: rephrased sys.excephook section about auditing events

[moritzvonberg]

Changed the phrasing of the section of sys.excepthook docs to be clearer.

This phrasing seems less prone to misunderstanding IMO.

• Issue: Slightly unclear phrasing of audit event section of sys.excepthook #138722

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📚 Documentation preview 📚: https://cpython-previews--138723.org.readthedocs.build/

[python-cla-bot]

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[MeGaGiGaGon]

For more context, while helping Mortiz in the Python discord, we both got stumped by this section of the docs. The issue with the existing phrasing is that there are two hook types - exception hooks and audit hooks. Since the last paragraph is not clear about which hook gets suppressed, we originally though it meant that the exception hook gets suppressed. This PR makes it clear that only the audit hooks have this special behavior around RuntimeErrors, and not the exception hooks.