Unsupport using Etcd as the registry in shardingsphere proxy

## Bug Report

[ERROR] 2024-11-06 09:19:40.998 [Etcd-EventListener-0] c.g.common.eventbus.EventBus.default - Exception thrown by subscriber method renew(org.apache.shardingsphere.mode.event.dispatch.state.compute.WorkerIdEvent) on subscriber org.apache.shardingsphere.mode.manager.cluster.event.subscriber.dispatch.ComputeNodeStateSubscriber@3265ef81 when dispatching event: org.apache.shardingsphere.mode.event.dispatch.state.compute.WorkerIdEvent@7282af36
java.lang.NullPointerException: Cannot invoke "java.lang.Integer.intValue()" because "workerId" is null
at org.apache.shardingsphere.infra.instance.ComputeNodeInstanceContext.lambda$updateWorkerId$1(ComputeNodeInstanceContext.java:123)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.accept(ForEachOps.java:184)
at java.base/java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:179)
at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:1024)
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509)
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499)
at java.base/java.util.stream.ForEachOps$ForEachOp.evaluateSequential(ForEachOps.java:151)
at java.base/java.util.stream.ForEachOps$ForEachOp$OfRef.evaluateSequential(ForEachOps.java:174)
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
at java.base/java.util.stream.ReferencePipeline.forEach(ReferencePipeline.java:596)
at org.apache.shardingsphere.infra.instance.ComputeNodeInstanceContext.updateWorkerId(ComputeNodeInstanceContext.java:123)
at org.apache.shardingsphere.mode.manager.cluster.event.subscriber.dispatch.ComputeNodeStateSubscriber.renew(ComputeNodeStateSubscriber.java:78)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at com.google.common.eventbus.Subscriber.invokeSubscriberMethod(Subscriber.java:85)
at com.google.common.eventbus.Subscriber$SynchronizedSubscriber.invokeSubscriberMethod(Subscriber.java:142)
at com.google.common.eventbus.Subscriber.lambda$dispatchEvent$0(Subscriber.java:71)
at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:31)
at com.google.common.eventbus.Subscriber.dispatchEvent(Subscriber.java:68)
at com.google.common.eventbus.Dispatcher$PerThreadQueuedDispatcher.dispatch(Dispatcher.java:109)
at com.google.common.eventbus.EventBus.post(EventBus.java:270)
at org.apache.shardingsphere.infra.util.eventbus.EventBusContext.post(EventBusContext.java:44)
at java.base/java.util.Optional.ifPresent(Optional.java:178)
at org.apache.shardingsphere.mode.manager.cluster.listener.GlobalMetaDataChangedListener.onChange(GlobalMetaDataChangedListener.java:39)
at org.apache.shardingsphere.mode.repository.cluster.etcd.EtcdRepository.lambda$dispatchEvent$3(EtcdRepository.java:191)
at java.base/java.util.concurrent.CompletableFuture$AsyncRun.run(CompletableFuture.java:1804)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1144)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:642)
at java.base/java.lang.Thread.run(Thread.java:1583)

Start with ComputeNodeInstanceContext.updateWorkerId at line 123 and follow the WorkerIdEvent flow through ComputeNodeStateSubscriber. Then inspect EtcdRepository.dispatchEvent to understand how Etcd changes reach the subscriber. Done means using Etcd as the ShardingSphere Proxy registry no longer produces the reported NullPointerException.

Written by the indexing model from the issue text.