fix: ensure read_loop properly closed when disposing transport

Author: owenpearson

ably/transport/websockettransport.py

@@ -231,8 +231,16 @@ async def dispose(self):
         self.is_disposed = True
         if self.read_loop:
             self.read_loop.cancel()
+            try:
+                await self.read_loop
+            except asyncio.CancelledError:
+                pass
         if self.ws_connect_task:
             self.ws_connect_task.cancel()
+            try:
+                await self.ws_connect_task
+            except asyncio.CancelledError:
+                pass
         if self.idle_timer:
             self.idle_timer.cancel()
         if self.websocket: