chore(cleanup): Remove unimported file pkg/config/config.go

[chansuke]

Closes #1137

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.60%. Comparing base (bf48261) to head (68b0634).
Report is 7 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1138      +/-   ##
==========================================
+ Coverage   63.49%   63.60%   +0.10%     
==========================================
  Files          15       15              
  Lines        2326     2341      +15     
==========================================
+ Hits         1477     1489      +12     
- Misses        758      760       +2     
- Partials       91       92       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.