## Is your feature request related to a problem?
See [this](https://github.com/PostHog/posthog/pull/9139/files/2754c0fd6633c806def5c328d491421ae7de0c19#diff-7f0217a57a02b6ebd709f6aa7bf43760b2d5a53069aee2b7fea27fdad1caadf1) for more info.


## Describe the solution you'd like

> This is used by django-rest-hooks, the library we use to integrate with Zapier. Specifically, this fires our Zapier integration's Triggers. However, the only trigger that actually matters is the "action_performed" one, and that has been completely delegated to the plugin server for a while. We can remove this Python cruft then, along with django-rest-hooks, but first we need to make sure action_defined and annotation_created actually are unused, and roll out an update to https://github.com/PostHog/posthog-zapier that'd remove those two completely.


## Describe alternatives you've considered

Do nothing
posthog/settings/web.py
import os
from datetime import timedelta
from typing import List
from posthog.settings.base_variables import BASE_DIR, DEBUG, TEST
from posthog.settings.statsd import STATSD_HOST
from posthog.settings.utils import get_from_env, get_list, str_to_bool
AXES_ENABLED = get_from_env("AXES_ENABLED", not TEST, type_cast=str_to_bool)
AXES_HANDLER = "axes.handlers.cache.AxesCacheHandler"
AXES_FAILURE_LIMIT = get_from_env("AXES_FAILURE_LIMIT", 30, type_cast=int)
AXES_COOLOFF_TIME = timedelta(minutes=10)
AXES_LOCKOUT_CALLABLE = "posthog.api.authentication.axes_locked_out"
AXES_META_PRECEDENCE_ORDER = ["HTTP_X_FORWARDED_FOR", "REMOTE_ADDR"]
INSTALLED_APPS = [
    "whitenoise.runserver_nostatic",  
    "django.contrib.admin",
    "django.contrib.auth",
    "django.contrib.contenttypes",
    "django.contrib.sessions",
    "django.contrib.messages",
    "django.contrib.postgres",