New Lightmapper denoising library includes deep neural network library that does not support 32 bits.

[madmiraal]

Godot version: master (00949f0)

OS/device including version: 32 bit platforms.

Issue description: The new lightmapper #38386 introduced a new denoising library: oidn that includes a Deep Neural Network library: oneDNN that only supports 64 bits:

oneDNN supports platforms based on the following architectures:

• Intel 64 or AMD64,
• Arm 64-bit Architecture (AArch64).

Steps to reproduce: Try compile master (with #38757 to avoid an earlier compilation error) using: scons -j8 platform=windows tools=yes bits=32 causes an assertion error:

static_assert(sizeof(void*) == 8, "Intel(R) MKL-DNN supports 64 bit only");

Minimal reproduction project: N/A

Furthermore it includes a warning about limited support on Arm processors.

WARNING
Arm 64-bit Architecture (AArch64) support is experimental with limited testing validation.

[akien-mga]

Its build should be restricted to tools=yes and desktop platforms, it won't be used in templates and even if we enable Android editor builds, it doesn't make sense to bake lightmaps on a mobile device.

I guess we can also disable it on 32-bit desktop builds.