## 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
model = Insight
        fields = [
            "id",
            "short_id",
            "name",
            "filters",
            "dashboard",
            "color",
            "description",
            "last_refresh",
            "refreshing",
            "saved",
            "updated_at",
        ]
        read_only_fields = ("short_id", "updated_at")
    def create(self, validated_data: Dict, *args: Any, **kwargs: Any) -> Any:
        raise NotImplementedError()
    def to_representation(self, instance):
        representation = super().to_representation(instance)
        representation["filters"] = instance.dashboard_filters()
        return representation
class InsightSerializer(TaggedItemSerializerMixin, InsightBasicSerializer):
    result = serializers.SerializerMethodField()
    last_refresh = serializers.SerializerMethodField()
    created_by = UserBasicSerializer(read_only=True)
    last_modified_by = UserBasicSerializer(read_only=True)
    effective_privilege_level = serializers.SerializerMethodField()
    class Meta: