Update Dockerfile and golang dependencies

What does this MR do?

The Dockerfile for this project was out of date, pulling in a mix of Debian and Alpine base images. One of the base images could be removed, so it was. Also, the golang dependencies needed an update, so that's taken care of here as well.

What are the relevant issue numbers?

• https://gitlab.com/gitlab-org/gitlab/-/issues/247073

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