test: make arch available in status files

Pull Request check-list

Please make sure to review and check all of these items:

• Does make -j8 test (UNIX) or vcbuild test nosign (Windows) pass with this change (including linting)?
• Is the commit message formatted according to CONTRIBUTING.md?

Affected core subsystem(s)

test

Description of change

The value is retrieved from process.arch in node itself.

Thanks to @joaocgreis for providing a similar implementation (mostly equal)

/cc @trott