[Vioshim]

This PR fixes the issue in which __loop_create_datagram_endpoint raises ValueError("unexpected address family") whenever both local_addr and remote_addr are omitted despite family being explicitly provided.

Allows the following

await loop.create_datagram_endpoint(
    protocol_factory,
    family=socket.AF_INET,
)

This improves compatibility with asyncio-based libraries that rely on unconnected UDP sockets, including dnspython's asynchronous resolver

[egorsmkv]

thank you for the contribution!