Fix data cleanup for API integration tests duplicateFeed, feedGeneratorsPerFeed, and feedCountsAccurate

Summary

The three API integration tests fail on an instance where they have run before, indicating an issue with data cleanup.

Is this a new feature?

• Yes, this is a new feature
• No, this is a change to existing functionality

Description of existing functionality

Navigate to /integrationtests and run the three aforementioned tests multiple times.

Recommended approach or architecture

Fix the data cleanup logic or fix these tests to pass idempotently.