🤖 Implement Singleton Initialization for Celery App and Database

[sentry-autofix]

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This fix was triggered by Jenn Mueng

Fixes SEER-9P

This pull request introduces a mechanism to prevent multiple initializations of the Celery application and database. A global flag, _bootup_complete, is added to the init_celery_app function to ensure that the bootup process occurs only once, regardless of how many times the initialization function is called. Similarly, a _db_initialized flag is introduced in the initialize_database function to guard against multiple calls, ensuring that the database configuration is set only once. This change enhances the robustness of the initialization process and prevents potential configuration conflicts.

If you have any questions or feedback for the Sentry team about this fix, please email [email protected] with the Run ID: 2192.