fix(ai): Fix update agent card failed by console. (#13948)

Change-Id: Id32b8127a4eff96eb49475ca0b2ee9355fb1ac17

Author: KomachiSion

ai/src/main/java/com/alibaba/nacos/ai/form/a2a/admin/AgentCardUpdateForm.java

@@ -16,6 +16,9 @@
 
 package com.alibaba.nacos.ai.form.a2a.admin;
 
+import com.alibaba.nacos.api.exception.api.NacosApiException;
+import com.alibaba.nacos.common.utils.StringUtils;
+
 import java.io.Serial;
 
 /**
@@ -42,4 +45,13 @@ public void setSetAsLatest(boolean setAsLatest) {
     protected void fillDefaultRegistrationType() {
         // Update does not need to fill registration type
     }
+    
+    @Override
+    protected void validateRegistrationType() throws NacosApiException {
+        // Update request if no set registration type, means not change the registration type
+        if (StringUtils.isEmpty(getRegistrationType())) {
+            return;
+        }
+        super.validateRegistrationType();
+    }
 }