## Is your feature request related to a problem?

There's only 2 files where we use pandas, but pandas is 49MB and numpy is another 86MB, slowing down builds massively.

## Describe the solution you'd like

Replace pandas with a pure SQL/Python solution in
- posthog/queries/trends.py
- posthog/queries/sessions.py

Both of those have equivalent examples in Clickhouse (ee/clickhouse) that don't use Pandas.

## Describe alternatives you've considered

Continue using Pandas and clogging builds

## Additional context



#### *Thank you* for your feature request – we love each and every one!

posthog/queries/test/test_trends.py
self._create_events()
            response = trends().run(Filter(data={"date_from": "2012-12-12"}), self.team)
            self.assertEqual(response, [])
        def test_interval_filtering(self):
            self._create_events(use_time=True)
            
            with freeze_time("2020-01-02"):
                response = trends().run(
                    Filter(data={"date_from": "2020-01-01", "interval": "minute", "events": [{"id": "sign up"}]}),
                    self.team,
                )
            self.assertEqual(response[0]["labels"][6], "Wed. 1 January, 00:06")
            self.assertEqual(response[0]["data"][6], 3.0)
            
            with freeze_time("2020-01-02"):
                response = trends().run(
                    Filter(data={"date_from": "2019-12-24", "interval": "hour", "events": [{"id": "sign up"}]}),
                    self.team,
                )
            self.assertEqual(response[0]["labels"][3], "Tue. 24 December, 03:00")
            self.assertEqual(response[0]["data"][3], 1.0)
            
            self.assertEqual(response[0]["data"][192], 3.0)