API-42295: Remove Appeals API OAuth Token Generation and Validation Rake Tasks

[kristen-brown]

Summary

This work is behind a feature toggle (flipper): NO

This PR removes the Appeals API OAuth token generation and validation rake tasks from the application. This can be done because 1) all Appeals APIs that use OAuth are moving out of vets-api and into a new application on a different VA platform, and 2) we have newer methods of generating and validating OAuth tokens for the Appeals API.

My team (Lighthouse Banana Peels) owns the Lighthouse Appeals APIs and were the original creators of the rake task that this PR removes.

Related issue(s)

• API-42295

Testing done

• New code is covered by unit tests – N/A, removed code only.

I ran bundle exec rake -T and validated that the deleted rake tasks are no longer returned in the list. I also confirmed that the removed settings were only used by these removed rake tasks.

Screenshots

N/A

What areas of the site does it impact?

This PR only impacts the Lighthouse Appeals APIs OAuth token generation and validation rake tasks.

Acceptance criteria

• I fixed|updated|added unit tests and integration tests for each feature (if applicable). – N/A
• No error nor warning in the console.
• Events are being sent to the appropriate logging solution
• Documentation has been updated (link to documentation) – N/A
• No sensitive information (i.e. PII/credentials/internal URLs/etc.) is captured in logging, hardcoded, or specs
• Feature/bug has a monitor built into Datadog (if applicable) – N/A
• If app impacted requires authentication, did you login to a local build and verify all authenticated routes work as expected
• I added a screenshot of the developed feature – N/A

Requested Feedback

No specific feedback requested for this PR.

[github-actions]

Error: A file (or its parent directories) was deleted but its reference still exists in CODEOWNERS. Please update the .github/CODEOWNERS file and delete the entry for the Offending file: rakelib/appeals_api_oauth.rake

[github-actions]

Backend-review-group approval confirmed.