refactor: Use SHSDuplexStream.close instead of disconnect

`disconnect()` is now deprecated to make the API more consistent.

ssb/packet_stream.py

@@ -229,7 +229,7 @@ class PacketStream:
 
                 if not read_data:
                     logger.debug("DISCONNECT")
-                    self.connection.disconnect()
+                    self.connection.close()
 
                     return None
 
@@ -240,7 +240,8 @@ class PacketStream:
             return PSMessage.from_header_body(flags, req, body)
         except StopAsyncIteration:
             logger.debug("DISCONNECT")
-            self.connection.disconnect()
+            self.connection.close()
+
             return None
 
     async def read(self) -> Optional[PSMessage]:
@@ -314,4 +315,4 @@ class PacketStream:
         """Disconnect the stream"""
 
         self._connected = False
-        self.connection.disconnect()
+        self.connection.close()