[Linux] Add armhf build.

[Faless]

EDIT: Rebased, updated to use the new arch scons option, and removed the special *_module_enabled=no which are no longer necessary.

Original message

Some modules are disabled due to incompatibilities:

• raycast (embree), we should fix detecetion in module config.py.
• etcpak, this likely also require at least aarch64 instructions to build.
• denoise (oneDNN), also needs fix in config.py (x86_64 only).
• theora (are we keeping this?).

We should probably wait and instead of merging this PR directly, wait for godotengine/godot#55778 or a light-weight version of it that fixes module detection (so we don't need the extra *_module_enabled=no shenanigan).

Depends on godotengine/build-containers#103
Ref godotengine/godot-proposals#988

[aaronfranke]

@Faless If you want to revisit this PR, it should be cleaner to do now that the PRs you've mentioned have been merged.

[Calinou]

@Faless Are you available to continue this PR? If not, I'd like to look into revisiting this after 4.2. Note that we can probably build only arm64 as I expect armhf binaries to be very slow for 4.x. Raspberry Pi 4 also finally uses a 64-bit OS by default, and so does the recently released Raspberry Pi 5.

denoise (oneDNN), also needs fix in config.py (x86_64 only).

Since Godot 4.2, OpenImageDenoise is no longer part of Godot itself (it's now an optional external program). The option to disable that module can be removed now.

[Faless]

Note that we can probably build only arm64

The reason for doing armhf build at the time was that we didn't (and still don't) have a arm64 buildroot.

I worked on a arm64 toolchain at the time but it was never finalized because IIRC there were concerns about it requiring the inclusion of LLVM for vulkan/gl headers (LLVMPipe/LavaPipe). As far as I know @hpvb is almost done working on it.

I think once that's solved adding the arm64 build shouldn't be too hard.
In the meantime, I've updated this PR, but I agree that only providing arm64 builds might make sense.

[akien-mga]

Superseded by #90.

For now I've opted for adding all builds (editor and templates for arm32 and arm64). We'll see if we want to reduce the list.