3D Viewer NPTH holes have no walls

Description

I noticed that NPTH holes (drill holes) in the 3D viewer do not have drill hole walls. You can see inside the hollow PCB.

Same situation in KICad 9.0.4

Steps to reproduce

1. Open a layout (with a NPTH hole) in the 3D Viewer
2. Zoom into the hole

KiCad Version

Application: KiCad 3D Viewer x64 on x64

Version: 9.99.0-3016-g6a171e11fb, debug build

Libraries:
	wxWidgets 3.3
	FreeType 2.13.3
	HarfBuzz 10.2.0
	FontConfig 2.15.0
	libcurl/8.13.0-DEV Schannel zlib/1.3.1

Platform: Windows 10 (build 19045), 64-bit edition, 64 bit, Little endian, wxMSW
OpenGL: NVIDIA Corporation, NVIDIA GeForce GTX 1650/PCIe/SSE2, 4.6.0 NVIDIA 580.97

Build Info:
	Date: Sep  2 2025 14:30:14
	wxWidgets: 3.3.0 (wchar_t,STL containers)
	Boost: 1.88.0
	OCC: 7.9.1
	Curl: 8.13.0-DEV
	ngspice: 44
	Compiler: Visual C++ 1944 without C++ ABI

Build settings:
	KICAD_IPC_API=ON
	KICAD_USE_PCH=OFF
	KICAD_STDLIB_DEBUG=OFF
	KICAD_STDLIB_LIGHT_DEBUG=OFF
	KICAD_SANITIZE_ADDRESS=OFF
	KICAD_SANITIZE_THREADS=OFF

Locale: 
	Lang: de_DE
	Enc: UTF-8
	Num: 1.234,5
	Encoded кΩ丈: D0BACEA9E4B888 (sys), D0BACEA9E4B888 (utf8)