chore(deps): keep ty at 0.0.73

ty 0.0.74+ de-sugars `**kwargs: Unpack[<open TypedDict>]` with a trailing
`**kwargs: object`, which makes the `EnqueueLinksFunction` overloads and
`Dataset.export_to` fail `invalid-overload`. That behavior is intentional
(astral-sh/ty#4212, python/typing#2272), so the real fix is `closed=True` on
those TypedDicts, which requires splitting three public inheritance chains.

Author: vdusek