fix(types): Replace TypedDict inheritance with Protocol to avoid mypy crash

[mchen-sentry]

This PR addresses the mpy crash error AssertionError: Must not defer during final iteration on src/sentry/deletions.

The recent change to reference ActorSerializerResponse instead of UserSerializerResponse introduced a new complex TypedDict to resolve in the inheritance chain, causing mypy to run out of iterations.

This bandaid fix skips the resolution WebhookGroupResponse --> BaseGroupSerializerResponse --> ActorSerializerResponse. Runtime behavior is identical, although we do lose type information. Another alternative solution is moving ActorSerializerResponse to a module outside of the SCC (e.g. to user.py).

Ideally we'd like to refactor the wildcard imports in src/sentry/api/serializers/models/__init__.py (creates a 2000+ module SCC).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff            @@
##           master   #102605   +/-   ##
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  Coverage   80.89%    80.89%           
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  Files        8864      8864           
  Lines      390631    390696   +65     
  Branches    24839     24839           
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+ Hits       316013    316070   +57     
- Misses      74252     74260    +8     
  Partials      366       366           

[joshuarli]

mypy src/sentry/deletions/__init__.py passes with this patch applied to 85b873ec3d9fbc6ec38f7c63fe83e832391ecb27. Same with other complex inits like mypy src/sentry/grouping/enhancer/__init__.py.

Good bandaid for now, but still unclear to me how to debug this kind of thing.