Revert "For many linux build, use aarch64 instead of arm64"

[NikolajBjorner]

Reverts #7147

aarch64 directive isn't supported for the python build.
One of the following options may resolve this:

• add AARCH64 directives explicitly for LInux to scripts/mk_util.py.
• There is not much specific for ARM64+linux at this point. Perhaps passing in ARM64 would do, but then the wheel would also work if you renamed it from arm64 to aarch64 (this would be a simpler solution).
• use the cmake build system instead of the python (legacy) for the unix distribution. It is rehearsed in some situations, but getting the final bits and pieces right has taken me several iterations before. Experimenting with a self-contained action/pipeline for this may be easier so the pipeline/action can be tested without requiring to run Nightly.yaml, which is not generally triggered.