[Build] ci: run all native tests on arm64 runners too!

[DHowett]

The build pipeline rewrite in #34984 afforded us a better understanding of the build phases.

This pull request adds a test step to ARM64 that runs the test binaries which couldn't be run during compilation.

It might be slower due to lack of caching, but it sure beats not having ARM64 tests.

[snickler]

@DHowett - Need any assistance on this effort? :)