Remove Cohorts limit by dropping false dependency on Usage Ping

What does this MR do?

This MR removes the artificial limitation of not being able to use Cohorts when having the usage ping disabled. All data in the Cohorts feature is available with usage ping disabled, so this would qualify as an 'artificial limitation', and subsequently would need to be de-limited to comply with the stewardship promises of GitLab.

5. The open source codebase will not contain any artificial limits (repositories, users, size, performance, etc.)

- Our stewardship of GitLab, Promises (https://about.gitlab.com/company/stewardship/#promises)

see also: #30386

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