build: remove old Discord notify workflow

.github/workflows/discord.yml

@@ -1,43 +0,0 @@
-name: Discord notifications
-
-on:
-  release:
-    types:
-      - published
-  workflow_run:
-    workflows: ["Build and Publish"]
-    types:
-      - completed
-
-env:
-  DISCORD_WEBHOOK: ${{ secrets.DISCORD_WEBHOOK }}
-
-jobs:
-  discord:
-    runs-on: ubuntu-latest
-    timeout-minutes: 5
-    if: github.repository_owner == 'itzg'
-    steps:
-      - name: on-publish
-        if: github.event_name == 'release' && github.event.action == 'published'
-        uses: SethCohen/github-releases-to-discord@v1.20.0
-        with:
-          webhook_url: ${{ secrets.DISCORD_WEBHOOK }}
-      - name: on-success
-        if: github.event.workflow_run.conclusion == 'success'
-        uses: Ilshidur/action-discord@master
-        with:
-          args: |
-            Github repo: ${{ github.repository }}
-            - Branch: ${{ github.event.workflow_run.head_branch }}
-            - [Link: to Actions](<${{ github.event.workflow_run.html_url }}>)
-            - Status: 🎉  ${{ github.event.workflow_run.conclusion }}  🍏
-      - name: on-failure
-        if: github.event.workflow_run.conclusion == 'failure'
-        uses: Ilshidur/action-discord@master
-        with:
-          args: |
-            Github repo: ${{ github.repository }}
-            - Branch: ${{ github.event.workflow_run.head_branch }}
-            - [Link: to Actions](<${{ github.event.workflow_run.html_url }}>)
-            - Status: 🤔  ${{ github.event.workflow_run.conclusion }}  💣💥