fix: required default false

--bug=1050885 --user=刘瑞斌 【应用编排】添加用户输入参数，直接触发默认值必填校验 https://www.tapd.cn/57709429/s/1638132

ui/src/workflow/nodes/base-node/component/UserFieldFormDialog.vue

@@ -110,7 +110,7 @@ const currentRow = computed(() => {
         return currentItem.value
     }
   } else {
-    return { input_type: 'TextInput', required: true, attrs: { maxlength: 20, minlength: 0 } }
+    return { input_type: 'TextInput', required: false, attrs: { maxlength: 20, minlength: 0 } }
   }
 })
 const currentIndex = ref(null)