remove broken issue label workflow

.github/workflows/label-sponsors.yml

@@ -1,18 +0,0 @@
-name: label-sponsors
-
-on:
-  pull_request:
-    types: [opened]
-  issues:
-    types: [opened]
-
-jobs:
-  label:
-    name: Add Sponsor Labels
-    runs-on: ubuntu-latest
-    steps:
-      - uses: ueberdosis/sponsor-action@v1.0-alpha
-        with:
-          label: sponsor 💖
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-