src: fix compiler warning in env.cc

This fixes the following warning:

    ../src/env.cc: In member function ‘void node::Environment::Exit(int)’:
    ../src/env.cc:946:77: warning: format ‘%llu’ expects argument of type ‘long long unsigned int’, but argument 4 has type ‘uint64_t {aka long unsigned int}’ [-Wformat=]
           fprintf(stderr, "(node:%d, thread:%llu) ", uv_os_getpid(), thread_id());
                                                                      ~~~~~~~~~~~^

PR-URL: nodejs#31020
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Chengzhong Wu <legendecas@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>

src/env.cc

@@ -943,7 +943,8 @@ void Environment::Exit(int exit_code) {
     if (is_main_thread()) {
       fprintf(stderr, "(node:%d) ", uv_os_getpid());
     } else {
-      fprintf(stderr, "(node:%d, thread:%llu) ", uv_os_getpid(), thread_id());
+      fprintf(stderr, "(node:%d, thread:%" PRIu64 ") ",
+              uv_os_getpid(), thread_id());
     }
 
     fprintf(