[Cherry-pick-1.15] Set hinting region to use for GetBucketRegion() in pkg/repository/config/aws.go

[reasonerjt]

Please indicate you've done the following:

• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file (make new-changelog) or comment /kind changelog-not-required on this PR.
• Updated the corresponding documentation in site/content/docs/main.

[codecov]

Codecov Report

Attention: Patch coverage is 16.66667% with 10 lines in your changes missing coverage. Please review.

Project coverage is 58.97%. Comparing base (f499025) to head (5ddb319).
Report is 2 commits behind head on release-1.15.

Files with missing lines	Patch %	Lines
pkg/repository/config/aws.go	0.00%	10 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           release-1.15    #8505      +/-   ##
================================================
- Coverage         59.00%   58.97%   -0.04%     
================================================
  Files               367      367              
  Lines             38903    38910       +7     
================================================
- Hits              22955    22947       -8     
- Misses            14485    14499      +14     
- Partials           1463     1464       +1     

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