Bump the E2E migration and upgrade Velero and plugin versions for 1.15

[blackpiglet]

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Fixes #(issue)

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• [x] Accepted the DCO. Commits without the DCO will delay acceptance.
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• [ ] Updated the corresponding documentation in site/content/docs/main.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 58.99%. Comparing base (c53ab20) to head (1831c7b). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8329 +/- ## ======================================= Coverage 58.99% 58.99% ======================================= Files 367 367 Lines 38847 38847 ======================================= Hits 22918 22918 Misses 14467 14467 Partials 1462 1462 ```

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