Fix error when reloading code in Sidekiq

What does this MR do?

This commit fixes the following error in development:

ArgumentError: A copy of Gitlab::Metrics::Transaction has been removed from the module tree but is still active!

What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/54320 https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23262

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer

Closes #54320 (closed)