Fix resetting of attributes in EntityRegistry.async_get_or_create

[emontnemery]

Proposed change

Fix resetting of attributes in EntityRegistry.async_get_or_create

EntityRegistry.async_get_or_create was defaulting all named parameters to None, which even though it is a valid value for most parameters was also interpreted as the caller not specifying a value.
This PR instead uses the UNDEFINED sentinel to distinguish between a None-value, and the caller not specifying any value.

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• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
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• Breaking change (fix/feature causing existing functionality to break)
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• This PR fixes or closes issue: fixes #
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[balloob]

I think that we can remove this line :)