[MTIAGraph][Pytorch][2.1/n] Add API to destroy graph C++ instance (pytorch#166806)

I missed this API for MTIAGraph in D84457757(pytorch#165963)

Differential Revision: [D86026706](https://our.internmc.facebook.com/intern/diff/D86026706/)

Pull Request resolved: pytorch#166806
Approved by: https://github.com/albanD
ghstack dependencies: pytorch#166805

Author: andyanwang

aten/src/ATen/detail/MTIAHooksInterface.h

@@ -156,6 +156,10 @@ struct TORCH_API MTIAHooksInterface : AcceleratorHooksInterface {
     return -1;
   }
 
+  virtual void mtiagraphDestroy(int64_t handle) const {
+    FAIL_MTIAHOOKS_FUNC(__func__);
+  }
+
   virtual void mtiagraphCaptureBegin(int64_t handle, MempoolId_t pool) const {
     FAIL_MTIAHOOKS_FUNC(__func__);
   }

torch/csrc/mtia/Module.cpp

@@ -19,7 +19,10 @@ struct _MTIAGraph {
 
   _MTIAGraph(bool keep_graph = false)
       : handle_(at::detail::getMTIAHooks().mtiagraphCreate(keep_graph)) {}
-  ~_MTIAGraph() = default;
+
+  ~_MTIAGraph() {
+    at::detail::getMTIAHooks().mtiagraphDestroy(handle_);
+  }
 
   void capture_begin(at::MempoolId_t pool) {
     at::detail::getMTIAHooks().mtiagraphCaptureBegin(handle_, pool);