remove useless workflow

.github/workflows/discord-notifier.yml

@@ -1,14 +0,0 @@
-name: Notify github activity on discord
-
-on:
-  repository_dispatch:
-    types: [org-workflow-bot]  # <-- requirement to trigger central workflows
-
-jobs:
-  notify:
-    runs-on: ubuntu-latest
-    steps:
-    - name: Discord notification
-      env:
-        DISCORD_WEBHOOK: ${{ secrets.DISCORD_WEBHOOK }}
-      uses: Ilshidur/action-discord@08d9328877d6954120eef2b07abbc79249bb6210