chore: improve nullish-checks in tests

[ST-DDT]

I tried enabling @typescript-eslint/no-unnecessary-condition but in the end only this changes made the code better.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 99.97%. Comparing base (acb8b52) to head (0b75bc1).
Report is 1 commits behind head on next.

Additional details and impacted files

@@           Coverage Diff            @@
##             next    #3081    +/-   ##
========================================
  Coverage   99.96%   99.97%            
========================================
  Files        2776     2776            
  Lines      226260   226260            
  Branches      590      943   +353     
========================================
+ Hits       226178   226195    +17     
+ Misses         82       65    -17     

see 2 files with indirect coverage changes