`Qdrant`: to return `int` on `delete_by_filter(self)` so that the `DocumentStore` `Protocol` can be extended

[davidsbatista]

Extending the DocumentStore Protocol to have these 3 operations:

delete_all_documents(self) -> None
update_by_filter(self, filters: dict[str, Any], meta: dict[str, Any]) -> int
delete_by_filter(self, filters: dict[str, Any]) -> int

is only blocked by Qdrant’s delete_by_filter (and delete_by_filter_async) returning None instead of int.

Fix Qdrant by counting before delete since the client’s result does not provide it then we can safely add all three methods to the Protocol