FYST-509 Add Federal Taxable Income interest information to NC400 Schedule S xml and pdf

[arinchoi03]

Link to pivotal/JIRA issue

• https://codeforamerica.atlassian.net/browse/FYST-509

Is PM acceptance required? (delete one)

• Yes - don't merge until JIRA issue is accepted!

Reminder: merge main into this branch and get green tests before merging to main

What was done?

• Utilized the existing fed_taxable_income attr reader to set the value on NC400 Schedule S line 18 ("USInterestInc")
• I also removed the instructions page of the NC400-TY2024.pdf AND ncD400-Schedule-S-TY2024.pdf

How to test?

• Describe the testing approach taken to verify the changes, including:
  • Unit/manual tests
  • Test data used: Laney QSS is the only one that has fed_taxable_income but you can also edit this value for other fixtures if desired.
• Specify any relevant testing environments used: development/please use heroku for acceptance

Screenshots (for visual changes)

[github-actions]

Heroku app: https://gyr-review-app-4955-b7a43a589a90.herokuapp.com/
View logs: heroku logs --app gyr-review-app-4955 (optionally add --tail)