## 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
ee/tasks/hooks.py
import json
import requests
from celery.task import Task
from django.core.serializers.json import DjangoJSONEncoder
class DeliverHook(Task):
    max_retries = 3
    ignore_result = True
    def run(self, target: str, payload: dict, hook_id: str) -> None:
        try:
            response = requests.post(
                url=target,
                data=json.dumps(payload, cls=DjangoJSONEncoder),
                headers={"Content-Type": "application/json"},
            )
            if response.status_code == 410 and hook_id:
                
                from ee.models.hook import Hook
                Hook.objects.filter(id=hook_id).delete()
                return
            if response.status_code >= 500:
                response.raise_for_status()
        except requests.ConnectionError:
            delay_in_seconds = 2**self.request.retries
            self.retry(countdown=delay_in_seconds)