Add support to release Linux aarch64 wheels

[odidev]

On Linux aarch64, ‘pip install SimpleITK’ should download the wheels from pypi.

@blowekamp Please let me know your interest in releasing aarch64 wheels. I can help in this.

To start with I have tried to build wheels for amd64 using steps mentioned here but the script is giving below error -

+ ninja
[0/4] Performing configure step for 'SimpleITK-superbuild'
loading initial cache file /work/standalone-x64-build/SimpleITK-superbuild-prefix/tmp/SimpleITK-superbuild-cache-Release.cmake
CMake Error: The source directory "/work/SimpleITK/SuperBuild" does not appear to contain CMakeLists.txt.
Specify --help for usage, or press the help button on the CMake GUI.
FAILED: SimpleITK-superbuild-prefix/src/SimpleITK-superbuild-stamp/SimpleITK-superbuild-configure
cd /work/standalone-x64-build/sitk-sb && /usr/bin/cmake -C/work/standalone-x64-build/SimpleITK-superbuild-prefix/tmp/SimpleITK-superbuild-cache-Release.cmake -GNinja /work/SimpleITK/SuperBuild && /usr/bin/cmake -E touch /work/standalone-x64-build/SimpleITK-superbuild-prefix/src/SimpleITK-superbuild-stamp/SimpleITK-superbuild-configure
ninja: build stopped: subcommand failed.

Can you please suggest some pointers on the above error?

[blowekamp]

I would guess that the git submodule did not get initialized and cloned. When cloning you can use the flag –recurse-submodules with modern git versions. Otherwise, the following commands are needed:

git submodule init
git submodule init update