Removes vaOnlineSchedulingStatusImprovement from unit tests

[ryanshaw]

Note: This is part of a series of smaller PRs that breaks up the original large PR into more logical and reviewable chunks.

Summary

This removes the use of the unit tests within VA online scheduling. It is part of a set of PR's to address department-of-veterans-affairs/va.gov-team#55085. We no longer use this feature flag, so code behind this flag can be removed.

Related issue(s)

department-of-veterans-affairs/va.gov-team#55085

Testing done

• Unit testing
• e2e testing
• Manual local testing

Acceptance criteria

Quality Assurance & Testing

• I updated unit tests and integration tests for each feature (if applicable).
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Linting warnings have been addressed

Error Handling

• Browser console contains no warnings or errors.
• Events are being sent to the appropriate logging solution

Authentication

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