fix: slack messages action migration (#448)

Author: stelselim

.github/actions/slack-notification/action.yml

@@ -16,9 +16,10 @@ runs:
   using: "composite"
   steps:
     - name: Send Slack notification
-      uses: slackapi/slack-github-action@485a9d42d3a73031f12ec201c457e2162c45d02d # v2
+      uses: slackapi/slack-github-action@485a9d42d3a73031f12ec201c457e2162c45d02d  #v2
       with:
-        channel-id: ${{ inputs.channel-id }}
-        slack-message: ${{ inputs.message }}
-      env:
-        SLACK_BOT_TOKEN: ${{ inputs.bot-token }}
+        method: chat.postMessage
+        token: ${{ inputs.bot-token }}
+        payload: |
+          channel: "${{ inputs.channel-id }}"
+          text: "${{ inputs.message }}"