fix shadow rule (#5625)

examples/sharding-jdbc-example/orchestration-example/orchestration-raw-jdbc-example/src/main/resources/META-INF/nacos/local/shadow.yaml

@@ -47,10 +47,10 @@ dataSources:
     password: root
 
 rules:
-  - !SHADOW
-    column: shadow
-    shadowMappings:
-      ds: ds_0
+- !SHADOW
+  column: shadow
+  shadowMappings:
+    ds: ds_0
 
 props:
   sql.show: true

shadow-core/shadow-core-common/src/test/resources/yaml/shadow-rule.yaml

@@ -28,8 +28,8 @@ dataSources:
     password:
 
 rules:
-  - !SHADOW
-    column: shadow
-    shadowMappings:
-      ds: shadow_ds
+- !SHADOW
+  column: shadow
+  shadowMappings:
+    ds: shadow_ds