fix: close DockerHTTPClient session to prevent UnixConnector leak in Web Wireshark

The Web Wireshark WebSocket endpoint created a WebWiresharkManager but
never called close(), leaving the DockerHTTPClient's ClientSession with
UnixConnector unclosed when users closed the browser tab.

Also switch asyncio.wait in WebSocket proxy from ALL_COMPLETED to
FIRST_COMPLETED to avoid blocking cleanup when one direction disconnects.

gns3server/utils/websocket_to_websocket.py

@@ -127,7 +127,7 @@ async def websocket_proxy(
                 try:
                     done, pending = await asyncio.wait(
                         aws,
-                        return_when=asyncio.ALL_COMPLETED
+                        return_when=asyncio.FIRST_COMPLETED
                     )
                 except Exception as e:
                     log.error(f"asyncio.wait raised exception: {e}")
@@ -264,7 +264,7 @@ async def websocket_proxy_with_manual_accept(
                 try:
                     done, pending = await asyncio.wait(
                         aws,
-                        return_when=asyncio.ALL_COMPLETED
+                        return_when=asyncio.FIRST_COMPLETED
                     )
                     log.info(f"asyncio.wait returned. done={len(done)}, pending={len(pending)}")
                 except Exception as e: