Fix race when disabling config entries

[emontnemery]

Proposed change

Fix race when disabling config entries as reported in #47171
Also remove an unused constant reported here: https://github.com/home-assistant/core/pull/46779/files#r584294914

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)
• 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 Disabling a config entry triggers Entity removed twice error #47171

Checklist

• The code change is tested and works locally.
• Local tests pass. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.
• I have followed the development checklist
• The code has been formatted using Black (black --fast homeassistant tests)
• Tests have been added to verify that the new code works.

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• Documentation added/updated for www.home-assistant.io

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[MartinHjelmare]

Thanks!