v2 array tests: handle different hexdigests from zlib-ng (#1678)

[AdamWill]

As explained in the issue, zlib-ng produces different hex digests from original zlib. This adjusts the tests slightly to allow for this.

TODO:

• [ ] GitHub Actions have all passed
• [ ] Test coverage is 100% (Codecov passes)

Removed TODO items are irrelevant as this only changes tests.