## Bug description

I have lost edit permissions to a [dashboard I created](https://app.posthog.com/dashboard/28987), despite still being listed as the owner of the dashboard

## Expected behavior

I should still be able to edit the dashboard

## How to reproduce

I noticed this problem after adding a new insight, but this doesn't appear to be the cause of the issue. I've duplicated the dashboard to restore access and adding a new insight didn't appear to cause the issue 

## Environment

- [x] PostHog Cloud
- [ ] self-hosted PostHog (ClickHouse-based), version/commit: _please provide_
- [ ] self-hosted PostHog (Postgres-based, legacy), version/commit: _please provide_

## Additional context

#### *Thank you* for your bug report – we love squashing them!

posthog/api/insight.py
"created_at",
            "created_by",
            "last_modified_at",
            "last_modified_by",
            "short_id",
            "updated_at",
            "is_sample",
            "effective_restriction_level",
            "effective_privilege_level",
        )
    def create(self, validated_data: Dict, *args: Any, **kwargs: Any) -> Insight:
        request = self.context["request"]
        team = Team.objects.get(id=self.context["team_id"])
        validated_data.pop("last_refresh", None)  
        tags = validated_data.pop("tags", None)  
        if not validated_data.get("dashboard", None) and not validated_data.get("dive_dashboard", None):
            dashboard_item = Insight.objects.create(
                team=team, created_by=request.user, last_modified_by=request.user, **validated_data
            )
        elif validated_data["dashboard"].team == team:
            created_by = validated_data.pop("created_by", request.user)
            dashboard_item = Insight.objects.create(
                team=team, last_refresh=now(), created_by=created_by, last_modified_by=created_by, **validated_data
            )
        else:
            raise serializers.ValidationError("Dashboard not found")
        
        self._attempt_set_tags(tags, dashboard_item)
        return dashboard_item
    def update(self, instance: Insight, validated_data: Dict, **kwargs) -> Insight: