源码问题，TxManagerLocator中使用AtomicReference的问题。

在`org.dromara.raincat.core.service.impl.TxManagerLocator`中存储server列表的部分使用的是`AtomicReference`。这里的修改部分又加了锁，如果不用原子类，直接用`volatile`不可以吗。

Start in org.dromara.raincat.core.service.impl.TxManagerLocator and inspect how the server list is stored, updated, and protected by the existing lock. Compare the AtomicReference usage with the locking behavior and Java visibility requirements. Done requires a documented, justified decision about whether the current type should change, along with any affected tests or evidence.

Written by the indexing model from the issue text.