src: add virtual desctructor to Options class

Currently the Options class has a virtual function but no virtual
destructor which means that if delete is called on a Options pointer
to a derived instance, the derived destructor will not get called.

The following warning is currently being printed when
compiling:

warning: delete called on non-final 'node::PerIsolateOptions' that has
virtual functions but non-virtual destructor [-Wdelete-non-virtual-dtor]
    delete __ptr;

This commit adds a virtual destructor.

PR-URL: #23215
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: danbev

src/node_options.h

@@ -24,6 +24,7 @@ struct HostPort {
 class Options {
  public:
   virtual void CheckOptions(std::vector<std::string>* errors) {}
+  virtual ~Options() {}
 };
 
 // These options are currently essentially per-Environment, but it can be nice