feat: PR labels (#3002)

[muenchdo]

closes #3002

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[codecov]

Codecov Report

Attention: Patch coverage is 52.00000% with 12 lines in your changes missing coverage. Please review.

Project coverage is 51.45%. Comparing base (aecc74f) to head (321ec4c).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/gitprovider/github/github.go	47.82%	11 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3118      +/-   ##
==========================================
+ Coverage   51.26%   51.45%   +0.19%     
==========================================
  Files         283      283              
  Lines       25563    25584      +21     
==========================================
+ Hits        13104    13164      +60     
+ Misses      11762    11713      -49     
- Partials      697      707      +10     

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[muenchdo]

@krancour I went down the rabbit hole of adding tests for the GitHub provider. Please let me know if this is generally going in a direction you like or whether the added complexity for these new tests is too much.