Drop bgfx mention from UpdateDevice doc-comment

bgfx is an implementation detail not part of the public Device API surface;
the doc-comment should describe behavior in terms of the public API
(EnableRendering / DisableRendering / etc).

[Created by Copilot on behalf of @bghgary]

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: bghgary

Core/Graphics/Include/Shared/Babylon/Graphics/Device.h

@@ -113,13 +113,13 @@ namespace Babylon::Graphics
 
         void UpdateWindow(WindowT window);
 
-        // Sets the underlying graphics device that bgfx is initialized with on the next
-        // EnableRendering call.
+        // Sets the underlying graphics device used for rendering. The new device takes effect on
+        // the next EnableRendering call.
         //
-        // This API is only valid when rendering is disabled. Calling it while rendering is
-        // enabled throws std::runtime_error: bgfx is already initialized with the previous device
-        // and the swap would otherwise be silently buffered until the caller happens to do a
-        // DisableRendering / EnableRendering cycle, leading to bugs that are hard to diagnose.
+        // This API is only valid when rendering is disabled. Calling it while rendering is enabled
+        // throws std::runtime_error: the swap would otherwise be silently buffered until the caller
+        // happens to do a DisableRendering / EnableRendering cycle, leading to bugs that are hard
+        // to diagnose.
         //
         // The typical call sequence to swap to a new device (e.g. on D3D11 / D3D12 device-removed
         // recovery) is: