feat: add a cron job to test OSV API on test instance

[hogo6002]

Our test instance lacks real-life traffic, making it difficult to catch API query errors. Converting tools/api-performance-test into a cron job that runs for one hour daily. This job will send traffic to the test instance's API, helping us identify errors before deploying changes to production.

The tools/api-performance-test script will be deleted once the cron job is running stably.