In [56689], a ZIP file is needed in `tests/phpunit/data/filesystem/` but wasn't included in the changeset. This produced an error when attempting to create a subdirectory during the tests.
This adds the `tests/phpunit/data/filesystem/archive.zip` file.
Follow-up to [56689].
Props flixos90.
Fixes#37719.
git-svn-id: https://develop.svn.wordpress.org/trunk@56691 602fd350-edb4-49c9-b593-d223f7449a82
