Upgrade workhorse to 7.5.1

What does this MR do?

Upgrade workhorse to v7.5.1: Changelog https://gitlab.com/gitlab-org/gitlab-workhorse/blob/v7.5.1/CHANGELOG

Workhorse 7.5.1 contains exactly one change over v7.5.0:

• Rename correlation-id structured logging field to correlation_id gitlab-workhorse!343 (merged)

This change renames the logging field correlation-id to correlation_id for consistency with the other GitLab services.

What are the relevant issue numbers?

• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23694
• gitlab-workhorse!343 (merged)
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22844
• https://gitlab.com/gitlab-org/gitlab-ce/issues/55054
• https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/23666
• gitaly!995 (merged)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• 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