Add deterministic flag for DnCnn GPU-based tests

[Michael-T-McCann]

closes #104

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.39%. Comparing base (d4c0c3d) to head (604cd10).
Report is 720 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #105   +/-   ##
=======================================
  Coverage   90.39%   90.39%           
=======================================
  Files          42       42           
  Lines        3027     3027           
=======================================
  Hits         2736     2736           
  Misses        291      291           

Flag	Coverage Δ
unittests	90.39% <ø> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.