fix(backend): fix test assertation

[matmair]

follow up to #11896
replaces #11906

[netlify]

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Name	Link
🔨 Latest commit	a4f8f4d
🔍 Latest deploy log	https://app.netlify.com/projects/inventree-web-pui-preview/deploys/69ff2bb7d22b290008e43cbd

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.35%. Comparing base (04ef8a4) to head (a4f8f4d).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master   #11908      +/-   ##
==========================================
+ Coverage   91.32%   91.35%   +0.03%     
==========================================
  Files         972      972              
  Lines       50421    50421              
==========================================
+ Hits        46046    46063      +17     
+ Misses       4375     4358      -17     

Flag	Coverage Δ
backend	89.18% <100.00%> (+0.03%)	⬆️

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Components	Coverage Δ
Backend Apps	91.68% <100.00%> (+0.04%)	⬆️
Backend General	93.41% <ø> (ø)
Frontend	∅ <ø> (∅)

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