Move `derailed_benchmarks` into `test` group

What does this MR do?

Fixes https://gitlab.com/gitlab-org/gitlab/-/issues/217527
One of the possible fixes is to move derailed_benchmarks gem into test group:
In Omnibus, we install the gems with bundle install --without development test
(https://gitlab.com/gitlab-org/omnibus-gitlab/blob/069c1af5e393791ac7001e57e40bcaa05f50510c/config/software/gitlab-rails.rb#L94)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

N/A

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team