chore: Remove unnecessary fmt.Print in tests

[alexandear]

1. Remove fmt.Printf and fmt.Println from unit tests. Looks like they were used for debugging.
2. Configure the forbidigo linter to forbid fmt.Print statements.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.52%. Comparing base (ab5ad47) to head (0e1c294).
⚠️ Report is 3 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #3999   +/-   ##
=======================================
  Coverage   93.52%   93.52%           
=======================================
  Files         207      207           
  Lines       17597    17597           
=======================================
  Hits        16458    16458           
  Misses        938      938           
  Partials      201      201           

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[gmlewis]

Thank you, @alexandear!
LGTM.
Merging.