Updates CODEOWNERS for OCTO identity

[asg5704]

Summary

This PR fixes the CODEOWNERS file to change ownership of unit tests to OCTO-Identity. It also moves the sso.unit.spec.js file into the /tests/sso directory

Related issue(s)

• department-of-veterans-affairs/va.gov-team#82994

Testing done

Manual

Screenshots

n/a

What areas of the site does it impact?

n/a

Acceptance criteria

Quality Assurance & Testing

• [x] I update the CODEOWNERS file

Error Handling

• [ ] Browser console contains no warnings or errors.
• [ ] Events are being sent to the appropriate logging solution
• [ ] Feature/bug has a monitor built into Datadog or Grafana (if applicable)

Authentication

• [ ] Did you login to a local build and verify all authenticated routes work as expected with a test user

:warning: Team Sites (only applies to modifications made to the VA.gov header) :warning:

• [ ] The vets-website header does not contain any web-components
• [ ] I used the proxy-rewrite steps to test the injected header scenario
• [ ] I reached out in the #sitewide-public-websites Slack channel for questions

Requested Feedback

(OPTIONAL) What should the reviewers know in addition to the above. Is there anything specific you wish the reviewer to assist with. Do you have any concerns with this PR, why?