Fix CI- GUFE imports

[jthorton]

Adds standard to the testing env which is now needed by gufe following OpenFreeEnergy/gufe#438
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• I certify that this contribution is covered by the MIT License here and the Developer Certificate of Origin at https://developercertificate.org/.

[github-actions]

No API break detected ✅

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.81%. Comparing base (d2f4719) to head (431fad0).
Report is 154 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1060      +/-   ##
==========================================
- Coverage   94.55%   92.81%   -1.74%     
==========================================
  Files         134      134              
  Lines       10003    10003              
==========================================
- Hits         9458     9284     -174     
- Misses        545      719     +174     

Flag	Coverage Δ
fast-tests	92.81% <ø> (?)
slow-tests	?

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