Notify on issue creation only (#386)

Author: Callisto13

.github/workflows/fork.yaml

@@ -53,6 +53,7 @@ jobs:
           Auto-generated by [issue-bot](https://github.com/imjohnbo/issue-bot).
         labels: "area/firecracker, area/dependency, kind/feature, priority/critical-urgent"
     - name: Notify slack on creation success
+      if: ${{ success() && env.NEW_VERSION != '' }}
       uses: actions-ecosystem/action-slack-notifier@fc778468d09c43a6f4d1b8cccaca59766656996a
       with:
         slack_token: ${{ secrets.SLACK_TOKEN }}