chore: Remove matrix notification workflow

Signed-off-by: Krille <c.kussowski@famedly.com>

.github/workflows/matrix_notification.yaml

@@ -1,26 +0,0 @@
-name: Matrix Notification
-
-on:
-  issues:
-    types: [ opened ]
-  issue_comment:
-    types: [ created ]
-
-jobs:
-  notify:
-    runs-on: ubuntu-latest
-
-    steps:
-      - name: Send Matrix Notification
-        env:
-          MATRIX_URL: https://matrix.janian.de/_matrix/client/v3/rooms/${{ secrets.MATRIX_MANAGEMENT_ROOM }}/send/m.room.message
-        run: |
-          if [ "${{ github.event.action }}" == "opened" ]; then
-            PAYLOAD="{\"msgtype\": \"m.notice\", \"body\": \"New Issue from ${{ github.event.issue.user.login }}\\n${{ github.event.issue.title }}\\n\\n${{ github.event.issue.body }}\\n\\nURL: ${{ github.event.issue.html_url }}\"}"
-          elif [ "${{ github.event.action }}" == "created" ]; then
-            PAYLOAD="{\"msgtype\": \"m.notice\", \"body\": \"New Comment from ${{ github.event.comment.user.login }}\\n\\n${{ github.event.comment.body }}\\n\\nURL: ${{ github.event.comment.html_url }}\"}"
-          fi
-          curl -X POST -H "Authorization: Bearer ${{ secrets.MATRIX_BOT_TOKEN }}" \
-               -H "Content-Type: application/json" \
-               -d "$PAYLOAD" \
-               $MATRIX_URL