Fix cross platform builds and additional refinements

[prasannavl]

Summary

• Propagate C/CXXFLAGS properly for darwin builds.
• Add the win32 libs for additional dependencies taken on by Rust projects for mingw builds.
• Switch make.sh locale to en_US.UTF-8 from POSIX to workaround Apple systems.
• Modify linter to allow en_US.UTF-8 for shell scripts
• Remove forcing --platform on docker noarch.dockerfile workflow
• Enable cctools support for both aarch64 and x64 to build natively on both build hosts.
• Cleanup of misc experiments that's not meant for master.

Context

• Bitcoin depends overrides C/CXX instead of C/CXXFLAGS to override cross compilers for darwin.
• This results in incorrect propagation, as well inconsistent behaviors of overriding
  flags during boost builds.

Workaround

• For now, we keep the override the same, as there are other blockers to clean this up.
• However, we also pass down the same to C/CXXFLAGS correctly so it matches and propagates cleanly
  to the rest of the build.
• Remove boost overrides that'll end up failing building boost, since this also overrides sysroot,
  resulting in not finding the correct includes.