src: add overlooked handle to cleanup

The `Environment::destroy_ids_timer_handle` should be cleaned up
by `Environment::CleanupHandles()`. Fix that by adding it to the list.

This partially fixes a cctest.

Ref: #14206
PR-URL: #14749
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>

Author: addaleax

src/env.cc

@@ -76,6 +76,10 @@ void Environment::Start(int argc,
       reinterpret_cast<uv_handle_t*>(&idle_check_handle_),
       close_and_finish,
       nullptr);
+  RegisterHandleCleanup(
+      reinterpret_cast<uv_handle_t*>(&destroy_ids_timer_handle_),
+      close_and_finish,
+      nullptr);
 
   if (start_profiler_idle_notifier) {
     StartProfilerIdleNotifier();