Support Slack Incoming Webhook Message

[ericyangpan]

Self Checks

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1. Is this request related to a challenge you're experiencing?

I hope to use the Incoming Webhook feature provided by Slack to send messages to Slack

2. Describe the feature you'd like to see

I hope Dify can provide a built-in tool to support this feature

3. How will this feature improve your workflow or experience?

Add a new notification channel to my workflow

4. Additional context or comments

Add a new notification channel to my workflow

5. Can you help us with this feature?

• I am interested in contributing to this feature.