src: delete unused variable in env.h

PR-URL: #26451
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: gengjiawen

src/env.h

@@ -1053,7 +1053,6 @@ class Environment {
   TickInfo tick_info_;
   const uint64_t timer_base_;
   bool printed_error_ = false;
-  bool abort_on_uncaught_exception_ = false;
   bool emit_env_nonstring_warning_ = true;
   bool emit_err_name_warning_ = true;
   size_t makecallback_cntr_ = 0;