API crash because of bad URL parameters

[sentry]

Acceptance criteria

• URL matching or view logic prevents an error with a proper 4xx response.

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Sentry Issue: FLAGSMITH-API-5NF

ValueError: invalid literal for int() with base 10: 'org_3COWhASRXfhcdxVrd0wEjpQp4dg'
  File "django/db/models/fields/__init__.py", line 2128, in get_prep_value
    return int(value)

ValueError: Field 'id' expected a number but got 'org_3COWhASRXfhcdxVrd0wEjpQp4dg'.
(17 additional frame(s) were not displayed)
...
  File "features/views.py", line 861, in get_queryset
    return super().get_queryset().filter(identity__pk=self.kwargs["identity_pk"])  # type: ignore[no-untyped-call]