⚡️(dify) Include empty files require field

Required files variable to be sent even if empty in DifyAI v5.x+

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Refactor**
	- Enhanced chat message creation to support future file attachments.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/forge/blocks/difyAi/actions/createChatMessage.ts

@@ -59,6 +59,7 @@ export const createChatMessage = createAction({
             response_mode: 'blocking',
             conversation_id,
             user,
+            files: []
           },
         })
         .json()