Relax constraint on numpy during type checking

[DimitriPapadopoulos]

Since numpy/numpy#28034 has been resolved, try unpinning numpy.

Also, the version of google-crc32c is already constrained here:

zarr-python/pyproject.toml

Line 38 in 9f69611

'google-crc32c>=1.5',

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/user-guide/*.md
• Changes documented as a new file in changes/
• GitHub Actions have all passed
• Test coverage is 100% (Codecov passes)