Fix Counter Cache not being disabled for acts-on-taggable

What does this MR do?

Metrics forces class loading, and thus it forces load of ActsOnTaggable before defining a default configuration.

The problem is ordering of operations. 8_metrics.rb should be initialized after acts_on_taggable.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/30582 https://gitlab.com/gitlab-org/gitlab-ce/issues/32729