feat: seed api.announcements notification type

[cka-y]

Summary:
This pull request introduces a new notification type for API announcements and ensures that existing users who have opted in are properly subscribed. The main changes are:

• Created liquibase/changes_user/feat_1729.sql to:
  • Seed the notification_type table with a new 'api.announcements' type.
  • Backfill the notification_subscription table for users already opted in, ensuring no duplicate subscriptions are created.

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• Run the unit tests with ./scripts/api-tests.sh to make sure you didn't break anything
• Add or update any needed documentation to the repo
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
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[davidgamez]

Should we remove the is_registered_to_receive_api_announcements column if it's part of another issue? We will also need to modify the user migration task.