Avoid importing unused cpython array for compatibility with pypy

[hmaarrfk]

Do you have a changelog you want me to add a note in?

A good explanation as to why this is important
h5py/h5py#1514

[lindstro]

We keep the changelog locally. If you write a short note, I will include it with the next release.

Thanks for identifying this issue. I will merge once the tests pass.

[hmaarrfk]

I think the title says it all. Thanks!

[codecov-io]

Codecov Report

Merging #109 into develop will decrease coverage by 0.00%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #109      +/-   ##
===========================================
- Coverage    94.40%   94.40%   -0.01%     
===========================================
  Files          263      263              
  Lines        12683    12682       -1     
===========================================
- Hits         11973    11972       -1     
  Misses         710      710              

Impacted Files	Coverage Δ
python/zfpy.pyx	90.49% <ø> (-0.05%)	⬇️

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[GarrettDMorrison]

LGTM