## 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/dashboard.py
request = self.context["request"]
        validated_data["created_by"] = request.user
        team = Team.objects.get(id=self.context["team_id"])
        use_template: str = validated_data.pop("use_template", None)
        use_dashboard: int = validated_data.pop("use_dashboard", None)
        validated_data = self._update_creation_mode(validated_data, use_template, use_dashboard)
        tags = validated_data.pop("tags", None)  
        dashboard = Dashboard.objects.create(team=team, **validated_data)
        if use_template:
            try:
                create_dashboard_from_template(use_template, dashboard)
            except AttributeError:
                raise serializers.ValidationError({"use_template": "Invalid value provided."})
        elif use_dashboard:
            try:
                from posthog.api.insight import InsightSerializer
                existing_dashboard = Dashboard.objects.get(id=use_dashboard, team=team)
                existing_dashboard_items = existing_dashboard.items.all()
                for dashboard_item in existing_dashboard_items:
                    override_dashboard_item_data = {
                        "id": None,  
                        "dashboard": dashboard.pk,
                        "last_refresh": now(),
                    }
                    new_data = {
                        **InsightSerializer(dashboard_item, context=self.context,).data,
                        **override_dashboard_item_data,
                    }