Update stubs for trio 0.18.0

- Remove max_refill_bytes from SSL (python-trio/trio#959)
- Add synchronous close and context managers to the memory channels (python-trio/trio#1797)

trio-stubs/__init__.pyi

@@ -264,13 +264,19 @@ class MemorySendChannel(trio.abc.SendChannel[T_contra]):
     def clone(self: T) -> T: ...
     async def aclose(self) -> None: ...
     def statistics(self) -> _Statistics: ...
+    def close(self) -> None: ...
+    def __enter__(self) -> MemorySendChannel: ...
+    def __exit__(self, *exc: object) -> None: ...
 
 class MemoryReceiveChannel(trio.abc.ReceiveChannel[T_co]):
     def receive_nowait(self) -> T_co: ...
     async def receive(self) -> T_co: ...
     def clone(self: T) -> T: ...
     async def aclose(self) -> None: ...
     def statistics(self) -> _Statistics: ...
+    def close(self) -> None: ...
+    def __enter__(self) -> MemoryReceiveChannel: ...
+    def __exit__(self, *exc: object) -> None: ...
 
 # written as a class so you can say open_memory_channel[int](5)
 class open_memory_channel(Tuple[MemorySendChannel[T], MemoryReceiveChannel[T]]):
@@ -511,7 +517,6 @@ class SSLStream(trio.abc.Stream):
         server_hostname: Optional[str] = None,
         server_side: bool = False,
         https_compatible: bool = False,
-        max_refill_bytes: int = ...,
     ) -> None: ...
     def getpeercert(self, binary_form: bool = ...) -> ssl._PeerCertRetType: ...
     def selected_npn_protocol(self) -> Optional[str]: ...
@@ -536,7 +541,6 @@ class SSLListener(trio.abc.Listener[SSLStream]):
         ssl_context: ssl.SSLContext,
         *,
         https_compatible: bool = False,
-        max_refill_bytes: int = ...,
     ) -> None: ...
     async def accept(self) -> SSLStream: ...
     async def aclose(self) -> None: ...