Nacos ConfigCacheService.tryReadLock: 获取配置缓存读锁

The `tryReadLock` method in the `ConfigCacheService` class of Nacos is used to attempt to acquire a read lock on the configuration cache. This method is typically called before reading the configuration data from the cache.\n\nThe purpose of acquiring a read lock is to ensure thread safety when accessing the configuration cache. By acquiring a read lock, multiple threads can read the configuration data concurrently, as long as no thread is holding a write lock.\n\nIf the `tryReadLock` method successfully acquires the read lock, it returns `true`. Otherwise, if the read lock is already held by another thread, it returns `false`.