Add Kopia repository ownership issue in troubleshooting.md

[blackpiglet]

Thank you for contributing to Velero!

Please add a summary of your change

Does your change fix a particular issue?

Fixes #9007

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

All modified and coverable lines are covered by tests ✅

Project coverage is 60.29%. Comparing base (b0b5cc4) to head (c312928).
Report is 2 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #9039   +/-   ##
=======================================
  Coverage   60.29%   60.29%           
=======================================
  Files         378      378           
  Lines       42729    42729           
=======================================
  Hits        25763    25763           
  Misses      15417    15417           
  Partials     1549     1549           

☔ 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.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[kaovilai]

Thank you!

[kaovilai]

LGTM! This documentation addition provides helpful guidance for users encountering Kopia repository ownership conflicts.