Fix: Vulkan: Use after free when switching scenes

Unreported issue introduced from recent changes. (memory leak in immediate mode)

Pull Request: https://projects.blender.org/blender/blender/pulls/144116

source/blender/gpu/vulkan/vk_context.cc

@@ -48,10 +48,9 @@ VKContext::~VKContext()
     surface_texture_ = nullptr;
   }
   free_resources();
-  VKDevice &device = VKBackend::get().device;
-  static_cast<VKImmediate *>(imm)->deinit(device);
   delete imm;
   imm = nullptr;
+  VKDevice &device = VKBackend::get().device;
   device.context_unregister(*this);
 
   this->process_frame_timings();

source/blender/gpu/vulkan/vk_immediate.cc

@@ -23,14 +23,6 @@ namespace blender::gpu {
 
 static CLG_LogRef LOG = {"gpu.vulkan"};
 
-void VKImmediate::deinit(VKDevice &device)
-{
-  if (active_buffer_.has_value()) {
-    active_buffer_->free_immediately(device);
-    active_buffer_.reset();
-  }
-}
-
 uchar *VKImmediate::begin()
 {
   uint add_vertex = prim_type == GPU_PRIM_LINE_LOOP ? 1 : 0;

source/blender/gpu/vulkan/vk_immediate.hh

@@ -38,8 +38,6 @@ class VKImmediate : public Immediate {
   std::optional<VKBuffer> active_buffer_;
 
  public:
-  void deinit(VKDevice &device);
-
   uchar *begin() override;
   void end() override;