fix: Loosen StoreListActor.picture_url to str and add new API error type (#1038)

Regenerates the Pydantic models, TypedDicts, and literal aliases from
the [published OpenAPI
specification](https://docs.apify.com/api/openapi.json)
(`v2-2026-08-24T085852Z` -> `v2-2026-08-27T071624Z`), picking up the
spec fixes from apify/apify-docs#2859.

- `StoreListActor.picture_url` is now `str | None` instead of `AnyUrl |
None`. The API doesn't guarantee an RFC 3986 URI here - legacy Actors
can carry an empty or malformed `pictureUrl` - so such Store items no
longer fail validation.
- `ErrorType` gains `cannot-publish-actor-task`, returned with 400 by
`POST /v2/actor-tasks` and `PUT /v2/actor-tasks/{actorTaskId}`.
- `ActorNotice` gains a `NONE_TYPE_NONE = None` member. The spec now
lists `null` in the enum (the API does return `notice: null`); since the
field is typed `ActorNotice | None`, `None` still validates to plain
`None`, so this is cosmetic.

*✍️ Drafted by Claude Code*