Expose TimeoutError during google_travel_time config_flow

[eifinger]

Proposed change

If we can distinguish between a timeout and "something else" we should make that information available to the user.

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 Google travel time broken #107705
• This PR is related to issue:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
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[edenhaus]

Thanks @eifinger 👍