src: remove unused struct in test_inspector_socket.cc

PR-URL: https://github.com/nodejs/node/pull/26284
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

test/cctest/test_inspector_socket.cc

@@ -61,13 +61,6 @@ enum inspector_handshake_event {
   kInspectorHandshakeNoEvents
 };
 
-struct expectations {
-  std::string actual_data;
-  size_t actual_offset;
-  size_t actual_end;
-  int err_code;
-};
-
 static bool waiting_to_close = true;
 
 void handle_closed(uv_handle_t* handle) {