fix(service-registry): Fix etcd service version acquisition problem

- Update the EtcdConfigIT test case to use specific version numbers instead of general configurations
- Modify the EtcdDiscovery class to improve version information extraction logic
- Optimize code structure to improve readability and performance

demo/demo-etcd/test-client/src/main/java/org/apache/servicecomb/samples/EtcdConfigIT.java

@@ -94,7 +94,7 @@ private void testService() {
 
   private void testVersion() {
 
-    putValue("/servicecomb/config/version/production/demo-etcd/provider/application.properties",
+    putValue("/servicecomb/config/version/production/demo-etcd/provider/0.0.1/application.properties",
         "test3=version");
     putValue("/servicecomb/config/version/production/demo-etcd/provider/0.0.1/application.properties",
         "test4=version4");

service-registry/registry-etcd/src/main/java/org/apache/servicecomb/registry/etcd/EtcdDiscovery.java

@@ -21,6 +21,7 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.Collectors;
@@ -164,7 +165,15 @@ public List<String> findServices(String application) {
     waiter.executeTaskAsync(() -> {
       String prefixPath = basePath + "/" + application;
       List<KeyValue> endpointKv = getValuesByPrefix(prefixPath);
-      return endpointKv.stream().map(kv -> kv.getKey().toString(StandardCharsets.UTF_8)).collect(Collectors.toList());
+      return endpointKv.stream()
+          .map(kv -> kv.getKey().toString(StandardCharsets.UTF_8))
+          .map(key -> {
+            String[] parts = StringUtils.split(key, "/");
+            return parts.length > 5 ? parts[4] : null;
+          })
+          .filter(Objects::nonNull)
+          .distinct()
+          .collect(Collectors.toList());
     });
     return waiter.waitForCompletion();
   }