Fix TC038D.setpoint when not using unitful newval

[scasagrande]

Fixes #468

Fixes TC038D.setpoint setter when specifying a newval that does not include units via quantities.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.20%. Comparing base (a4e12e8) to head (81fb3a7).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #469   +/-   ##
=======================================
  Coverage   99.20%   99.20%           
=======================================
  Files          96       96           
  Lines        9648     9648           
=======================================
  Hits         9571     9571           
  Misses         77       77           

Flag	Coverage Δ
unittests	99.20% <100.00%> (ø)

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[serrapha]

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