Use weak_ptr for TrapHandler Callbacks

The lifetime of the `this` pointer in the trap callbacks could be invalid as the lifetime of the underlying `Buffer`/`Texture` object wasn't guaranteed, this commit fixes that by passing a `weak_ptr` of the objects into the callbacks which is locked during the callbacks and ensures that a destroyed object isn't accessed.

Co-authored-by: Billy Laws <blaws05@gmail.com>

app/src/main/cpp/skyline/gpu/texture_manager.cpp

@@ -87,6 +87,7 @@ namespace skyline::gpu {
 
         // Create a texture as we cannot find one that matches
         auto texture{std::make_shared<Texture>(gpu, guestTexture)};
+        texture->SetupGuestMappings();
         texture->TransitionLayout(vk::ImageLayout::eGeneral);
         auto it{texture->guest->mappings.begin()};
         textures.emplace(mappingEnd, TextureMapping{texture, it, guestMapping});