## Bug description

Creating a selector with an attribute isn't working at all.

`[data-attr="bla"]`

## Expected behavior

It should work

## How to reproduce

1. Create action
2. Add an attribute in the selector
3. 


## Additional context

The reason for this is that we store the attributes as `attr__data-attr` but we do not add `attr__` in the filtering. I am working on a solution.


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

posthog/models/event.py
filter: Dict[str, Union[F, bool]] = {}
        subqueries = {}
        for index, tag in enumerate(selector.parts):
            subqueries["match_{}".format(index)] = Subquery(
                Element.objects.filter(group_id=OuterRef("pk"), **tag.data)
                .values("order")
                .order_by("order")
                
                [tag.unique_order : tag.unique_order + 1]
            )
            filter["match_{}__isnull".format(index)] = False
            if index > 0:
                
                if tag.direct_descendant:
                    filter["match_{}".format(index)] = F("match_{}".format(index - 1)) + 1
                else:
                    
                    filter["match_{}__gt".format(index)] = F("match_{}".format(index - 1))
        return (subqueries, filter)
    def filter_by_element(self, filters: Dict, team_id: int):