[asyncio.protocols] Fix DatagramProtocol address type for IPv6 (#16116)

Author: nightcityblade

stdlib/asyncio/protocols.pyi

@@ -27,11 +27,9 @@ class BufferedProtocol(BaseProtocol):
 class DatagramProtocol(BaseProtocol):
     __slots__ = ()
     def connection_made(self, transport: transports.DatagramTransport) -> None: ...  # type: ignore[override]
-    # addr can be a tuple[int, int] for some unusual protocols like socket.AF_NETLINK.
-    # Use tuple[str | Any, int] to not cause typechecking issues on most usual cases.
-    # This could be improved by using tuple[AnyOf[str, int], int] if the AnyOf feature is accepted.
-    # See https://github.com/python/typing/issues/566
-    def datagram_received(self, data: bytes, addr: tuple[str | Any, int]) -> None: ...
+    # addr is a tuple[str, int] for IPv4 or tuple[str, int, int, int] for IPv6.
+    # It can also be a tuple[int, int] for unusual protocols like socket.AF_NETLINK.
+    def datagram_received(self, data: bytes, addr: tuple[Any, ...]) -> None: ...
     def error_received(self, exc: Exception) -> None: ...
 
 class SubprocessProtocol(BaseProtocol):