GitHub Action CI: Add Go source file format check (#6090)

https://github.com/XTLS/Xray-core/pull/6057#issuecomment-4364819830

And https://github.com/XTLS/Xray-core/pull/6149#issuecomment-4546876261

proxy/wireguard/server.go

@@ -162,7 +162,6 @@ func (s *Server) forwardConnection(dest net.Destination, conn net.Conn) {
 		Reader: buf.NewReader(conn),
 		Writer: buf.NewWriter(conn),
 	})
-
 	if err != nil {
 		errors.LogInfoInner(ctx, err, "connection ends")
 	}