Apple Silicon (mac-arm64) keeps its own wheel below; AWS Graviton +
Raspberry Pi + Asahi-Linux users build from source until the
manifold-csg-sys cross-compile is fixed upstream.

Root cause (separately tracked): manifold-csg-sys's build.rs drives
a CMake build that pulls TBB via FetchContent. The TBB sub-build
inside that nested CMake does NOT inherit our cross-compiler env
vars (CC_aarch64_unknown_linux_gnu / CXX_aarch64_unknown_linux_gnu)
or our .cargo/config.toml settings, so TBB compiles for the host
arch (x86_64) even though the rest of Manifold cross-compiles
correctly. The final aarch64 link then mixes architectures and
fails with "File in wrong format".

The cross-tooling install + cargo config landed in earlier commits
remains useful for native aarch64 hosts that build the wheel
in-place, so the workflow's apt install + .cargo/config.toml
entries are kept (just no longer exercised by CI).

All other v0.4.20 -> v0.4.25 changes (point cloud streaming +
IfcfastError, parallel mesh pass + bounded RAM, instancing,
quantization, m.to_gltf, csg-default, classify.py refactor) ship
to PyPI for the first time in this release — PyPI was stuck on
v0.4.23 because v0.4.24's sigstore step glitched and v0.4.25 hit
this aarch64 link error.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>