Remove unused IS_FLOAT32 and IS_WINDOWS from test_ode

[maresb]

In the process of convincing myself that conda-forge/pymc-feedstock#60 was a good idea, I checked for sys.platform usages, and found these unused variables. 😄 ✂️

I don't seem to have labels permissions, but I suggest no releasenotes and tests

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• Remove unused IS_FLOAT32 and IS_WINDOWS from test_ode

[codecov]

Codecov Report

Merging #6057 (2569f57) into main (9024c2b) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #6057   +/-   ##
=======================================
  Coverage   89.07%   89.07%           
=======================================
  Files          72       72           
  Lines       12931    12931           
=======================================
  Hits        11518    11518           
  Misses       1413     1413           

[twiecki]

Thanks @maresb!