enable thelper linter

[PaulYakow]

I hereby agree to the terms of the CLA available at: https://yandex.ru/legal/cla/?lang=en

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

Issue Number: #972

What is the new behavior?

Other information

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 81.25000% with 6 lines in your changes are missing coverage. Please review.

Project coverage is 67.66%. Comparing base (4315955) to head (a312f2d).
Report is 13 commits behind head on master.

Files	Patch %	Lines
internal/xtest/context.go	57.14%	3 Missing ⚠️
internal/xtest/test_condition.go	0.00%	2 Missing ⚠️
internal/xtest/waiters.go	83.33%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1022      +/-   ##
==========================================
+ Coverage   67.59%   67.66%   +0.07%     
==========================================
  Files         295      295              
  Lines       29891    29892       +1     
==========================================
+ Hits        20205    20227      +22     
+ Misses       8751     8739      -12     
+ Partials      935      926       -9     

Flag	Coverage Δ
	53.70% <81.25%> (+0.05%)	⬆️
go-1.21.x	69.21% <81.25%> (+0.02%)	⬆️
go-1.22.x	67.51% <81.25%> (+0.18%)	⬆️
integration	53.70% <81.25%> (+0.05%)	⬆️
macOS	39.42% <3.12%> (+0.01%)	⬆️
ubuntu	39.41% <3.12%> (-0.01%)	⬇️
unit	39.48% <3.12%> (+<0.01%)	⬆️
windows	39.44% <3.12%> (+0.03%)	⬆️
ydb-23.3	49.56% <81.25%> (+0.20%)	⬆️
ydb-24.1	53.54% <81.25%> (+0.12%)	⬆️

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