Fix Geo migration spec

What does this MR do and why?

This backports !154506 (merged) to 16-8-stable-ee.

The test was failing in CI because the Geo CI job artifact registry had cached the newer state of the columns that no longer had the success column. migrate! doesn't reset the column information. This change resets the state so that the migration spec passes.

To reproduce the failure, run:

CI=true bundle exec rspec ./ee/spec/migrations/geo/migrate_ci_job_artifacts_to_separate_registry_spec.rb

From https://gitlab.com/gitlab-org/gitlab/-/issues/462487#note_1911223919

MR acceptance checklist

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• This MR is backporting a bug fix, documentation update, or spec fix, previously merged in the default branch.
• The MR that fixed the bug on the default branch has been deployed to GitLab.com (not applicable for documentation or spec changes).
• This MR has a severity label assigned (if applicable).
• Set the milestone of the merge request to match the target backport branch version.
• This MR has been approved by a maintainer (only one approval is required).
• Ensure the e2e:package-and-test-ee job has either succeeded or been approved by a Software Engineer in Test.

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