Update public Go dependencies, fix lint and imports

What does this MR do?

Update logrus and testify and apply the changes the linter and goimports want.

I didn't update our GitLab-maintained packages because they seem to require being updated in lockstep and I'm sure someone else knows the changes to make off-hand.

What are the relevant issue numbers?

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer