Breaking change

Proposed change

Add a zero guard to inverse unit conversions in homeassistant.util.unit_conversion so a zero input no longer triggers a ZeroDivisionError. This fixes the zero-value energy distance scenario described in the issue #159036
Addresses the failing tests/util/test_unit_conversion.py case covering 0 KWh/100km → km/kWh.

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New integration (thank you!)
• New feature (which adds functionality to an existing integration)
• Deprecation (breaking change to happen in the future)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Additional information

• This PR fixes or closes issue: fixes Core - unit_conversion.py - inverse conversion causes ZeroDivisionError after unit change #159036
• This PR is related to issue:
• Link to documentation pull request:
• Link to developer documentation pull request:
• Link to frontend pull request:

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