## Bug description

Currently, decide endpoint takes 10+ seconds on kea.js.org.

This means that for first-time visitors autocapture nor session recording will be turned on for that long - losing valuable information.

When measuring this yesterday via shell ([slack thread](https://posthog.slack.com/archives/C0113360FFV/p1604951621008400)), the culprit was feature flags cohort checking. In this case, the cohort user was checked against was defined against the following action:

![Screenshot from 2020-11-10 11-41-32](https://user-images.githubusercontent.com/148820/98657215-49582e80-234a-11eb-9669-37d55e0d23bd.png)

Which currently looks through events of the data for that team.

## Expected behavior

Decide endpoint should use cached/materialized cohort ownership rather than calculating it on the fly.

## How to reproduce

1. Create an action with some selector
2. Create a cohort for has done action at any point
3. Create a feature flag using the cohort.
4. Measure /decide endpoint latency

## Environment

Cloud 

## Additional context

cc @EDsCODE who made it not time out by https://github.com/PostHog/posthog/pull/2299

#### *Thank you* for your bug report – we love squashing them!
posthog/celery.py
try:
        g = statsd.Gauge("%s_posthog_celery" % (settings.STATSD_PREFIX,))
        llen = get_client().llen("celery")
        g.send("queue_depth", llen)
    except:
        
        
        return
@app.task(ignore_result=True)
def update_event_partitions():
    with connection.cursor() as cursor:
        cursor.execute(
            "DO $$ BEGIN IF (SELECT exists(select * from pg_proc where proname = 'update_partitions')) THEN PERFORM update_partitions(); END IF; END $$"
        )
@app.task(ignore_result=True)
def clean_stale_partials():
    """Clean stale (meaning older than 7 days) partial social auth sessions."""
    from social_django.models import Partial
    Partial.objects.filter(timestamp__lt=timezone.now() - timezone.timedelta(7)).delete()
@app.task(ignore_result=True)
def status_report():
    from posthog.tasks.status_report import status_report
    status_report()
@app.task(ignore_result=True)
def run_session_recording_retention():