Quarantine create_project_spec.rb on staging only

What does this MR do?

This quarantines create_project_spec.rb from running on staging only. We believe failures on staging are due to 1000s of subgroups not having been removed yet as they should, causing a query to load a dropdown box to slow and making this test time out.

There is a pipeline job that is supposed to delete subgroups but it has not been working, issues to address that are https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/720 and #280555 (closed)

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

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

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