[L0 v2] make destructor of the legacy context virtual

so that v2::context will be appropriately destroyed

Author: igchor

source/adapters/level_zero/context.hpp

@@ -43,6 +43,9 @@ struct ur_context_handle_t_ : _ur_object {
 
   ur_context_handle_t_(ze_context_handle_t ZeContext) : ZeContext{ZeContext} {}
 
+  // Make sure this is virtual so that v2::context is appropriately destroyed
+  virtual ~ur_context_handle_t_() {}
+
   // A L0 context handle is primarily used during creation and management of
   // resources that may be used by multiple devices.
   // This field is only set at ur_context_handle_t creation time, and cannot