Put devops adoption tab behind EE Ultimate license check [RUN AS-IF-FOSS]

What does this MR do?

This MR has 2 purposes;

1. Rename the feature flag from devops_adoption to devops_adoption_feature
2. Add a license for the feature as devops_adoption at the Ultimate level

Feature flag / rollout issue (will need to be updated once this is merged) #271568 (closed)

Screenshots (strongly suggested)

Ultimate license	Other

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

Related to #273406 (closed)