Fix local calendar handling of empty recurrence ids

[allenporter]

Proposed change

Fix bug when editing or deleting existing calendar events which fails with:

Error handling Calendar Event call: Unable to parse date/time value: [ValueError("Expected value to match DATE pattern: ''"), ValueError('Expected value to match DATE-TIME pattern: ')]

The frontend currently passes in an empty string for the recurrence_id which is then attempted to be parsed as an event id instance. This fixes the schema parser to ignore empty strings and treat them as none.

Alternatives:

• An alternative could be to patch ical to handle this, but I like the idea of passing None explicitly into the entity APIs.
• Another alternative could be to fix the frontend to omit the recurrence id but I leaned towards this to just keep the code as defensive

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 Local Calendar can't edit or delete #112561
• This PR is related to issue:
• Link to documentation pull request:

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[home-assistant]

Hey there @home-assistant/core, mind taking a look at this pull request as it has been labeled with an integration (calendar) you are listed as a code owner for? Thanks!

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[balloob]

This works.

I think that we might want to teach the frontend to sent in None instead of empty strings too.

[UK-JustinSmall]

OK can someone please let me know what I need to do to get this fixed in home assistant? Seems ticket got marked as fixed but problem still appears in mine.