Bump gitlab-exporter to 10.2.0

What does this MR do?

Update gitlab-exporter to v10.2.0, which addresses a problem with running gitlab-exporter on Puma.

See gitlab-org/omnibus-gitlab#6090 (closed)

NOTE: Requires gitlab-org/build/CNG!647 (merged)

Related issues

gitlab-org/omnibus-gitlab#6090 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion.

Required

• Merge Request Title and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for omnibus-gitlab opened: gitlab-org/omnibus-gitlab!5181 (merged)