fix: free IsolateData in ~NodeEnvironment (#28469)

This seems to just have been missing here, leaking memory
(and breaking the API contract for Node.js embedding).

shell/browser/javascript_environment.cc

@@ -363,7 +363,9 @@ void JavascriptEnvironment::OnMessageLoopDestroying() {
 NodeEnvironment::NodeEnvironment(node::Environment* env) : env_(env) {}
 
 NodeEnvironment::~NodeEnvironment() {
+  auto* isolate_data = env_->isolate_data();
   node::FreeEnvironment(env_);
+  node::FreeIsolateData(isolate_data);
 }
 
 }  // namespace electron