Rake task for adding container registry config to settings

What does this MR do?

This is step 3 of 3 in implementing #204839 (closed).

This adds a rake task that can be used to ping the container registry and update the ApplicationSettings added in step 1: !31125 (merged). It will add the vendor, version, and features to the application settings, which will eventually be used to gate features based on whether an instance is using the GitLab container registry or a 3rd party registry.

The rake task is not used here, it will be called by omnibus during an instance reconfiguration which will be handled in this separate issue: #214251 (closed)

Screenshots

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

Notes

Coauthored with @jdrpereira

Related to #204839 (closed)