refactor(yaml): remove repeat helper function

[timreichen]

• replaces repeat helper function with built in String.prototype.repeat()

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 80.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 95.81%. Comparing base (6a28a21) to head (72fc6ef).

Files	Patch %	Lines
yaml/_dumper.ts	50.00%	1 Missing :warning:
yaml/_loader.ts	83.33%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #5303 +/- ## ========================================== - Coverage 95.81% 95.81% -0.01% ========================================== Files 457 457 Lines 37893 37879 -14 Branches 5568 5567 -1 ========================================== - Hits 36307 36293 -14 Misses 1546 1546 Partials 40 40 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.