Remove state when entity is removed from registry

[emontnemery]

Proposed change

When removing an entry from entity registry, also remove it from the state machine.

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

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.

[balloob]

I think that this change makes sense:

Entity registry controls an entity. Updates to the registry already update name or remove the entity if disabled_by is set. This change makes sense.

We do have to make sure to check all async_removed_from_registry calls to make sure that this is handled correctly.

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (dev@2365e2e). Click here to learn what that means.
The diff coverage is 100%.

@@          Coverage Diff           @@
##             dev   #32184   +/-   ##
======================================
  Coverage       ?   94.75%           
======================================
  Files          ?      768           
  Lines          ?    55647           
  Branches       ?        0           
======================================
  Hits           ?    52726           
  Misses         ?     2921           
  Partials       ?        0

Impacted Files	Coverage Δ
homeassistant/helpers/entity.py	97.65% <100%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 2365e2e...9c0a07a. Read the comment docs.

[stale]

There hasn't been any activity on this pull request recently. This pull request has been automatically marked as stale because of that and will be closed if no further activity occurs within 7 days.
Thank you for your contributions.

[balloob]

Let's merge it and see how it goes.