VDB 12.0.0 Release

[danrbailey]

The release branch for VDB 12.0.0. This bumps the version up, updates the change log and makes a small fix to the CI docs workflow.

This also bumps up a number of minimum versions for our dependencies. We now support the VFX Reference Platforms 2023, 2024, 2025. These are the most notable version bumps:

• CMake 3.18 -> 3.20
• GCC 9.3.1 -> 11.2.1 (C++ ABI=0 no longer supported)
• MSVC 2019 -> MSVC 2022
• Python 3.9 -> 3.10
• Boost 1.73 -> 1.80
• LLVM 10.0.0 -> 13.0.0

I have also updated the CI accordingly. Finally, the address sanitizer picked up a bug in the RootNode, which I have also fixed (using emplace for an existing element in one case).

[apradhana]

I think the error should be ABI = 13 is still in active development.

[apradhana]

Thanks for addressing my comments. Other than my comment on setting the minimum NanoBind version, everything else looks good. Once all the CIs passed, this looks good.

[Idclip]

GCC 9.3.1 -> 11.2.1 (C++ ABI=0 no longer supported)

Can you still build with ABI=11 and the old C++ ABI?

[danrbailey]

GCC 9.3.1 -> 11.2.1 (C++ ABI=0 no longer supported)

Can you still build with ABI=11 and the old C++ ABI?

Yes, it still works. In fact the only thing we do regarding ABI currently is trying to align with Houdini's ABI (https://github.com/AcademySoftwareFoundation/openvdb/blob/master/cmake/OpenVDBHoudiniSetup.cmake#L349) and I didn't remove that logic in this release. Otherwise, you get whatever the compiler/compiler flags request.

However, it's not guaranteed to continue working. I removed all the CI jobs that test with GCC 9 / ABI=0 and if you build with GCC 9, you'll get a warning that it is unsupported which you have to suppress.

[Idclip]

minor comments about the llvm ci, otherwise lgtm, thanks a lot @danrbailey