Build x86_64 and aarch64 for macOS Examples

The "Bundle" workflow currently only creates a Debug macOS artifact that is built in the architecture of the underlying runner. Currently, this means that it is generating an x86_64 binary -- since apparently this is the default runner.

This task is to track making the workflow build both `aarch64` and `x86_64` architectures, and releasing both binaries. This will require some level of testing, since cross-compiling is locally causing issues with SDL compilation. It's unclear if this is an issue with the use of the internal `cmake` build dependency, or whether this is something easier to fix.