chore: update discord release workflow

Author: bjarn

.github/workflows/release-to-discord.yml

@@ -1,13 +1,15 @@
 name: Release to Discord
 
 on:
-  release:
-    types: [ published ]
+  workflow_run:
+    workflows: ["Release"]
+    types: [completed]
   workflow_dispatch:
 
 jobs:
   github-releases-to-discord:
     runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' || github.event_name == 'workflow_dispatch' }}
     steps:
       - name: Checkout
         uses: actions/checkout@v6