Implement caching for /check/yorkie endpoint to improve performance

[devleejb]

Description:
Currently, the /check/yorkie endpoint is provided for Authentication Webhook usage, but it performs a database call on each request. To enhance the performance of this endpoint, implementing a caching mechanism is strongly recommended. This will reduce the number of database calls and improve response time for repeated requests.

Why:
Adding caching will significantly improve the performance and scalability of the Authentication Webhook feature by reducing latency and database load, which is crucial for applications that expect high traffic and quick responses.