chore(toolkit-lib): remove duplicate test helpers

[mrgrain]

This PR removes duplicate test helper functions in the toolkit-lib package to improve code maintainability and reduce redundancy.

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 78.98%. Comparing base (ea4ba36) to head (ce1d0da).

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #507   +/-   ##
=======================================
  Coverage   78.98%   78.98%           
=======================================
  Files          46       46           
  Lines        6994     6994           
  Branches      776      775    -1     
=======================================
  Hits         5524     5524           
  Misses       1452     1452           
  Partials       18       18           

Flag	Coverage Δ
suite.unit	78.98% <ø> (ø)

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