remove workflow that doesn't work at this time (#8511)

.github/workflows/sustain-bugs.yml

@@ -1,23 +0,0 @@
-name: sustain
-
-on:
-  issues:
-    types: [labeled]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-    env: 
-      PROJECT_COLUMN_ID: ${{secrets.PROJECT_COLUMN_ID}}
-    steps:
-    - name: Maybe move an issue to the project board
-      uses: actions/github-script@0.8.0
-      if: github.event.label.name == 'bug'
-      with: 
-        github-token: ${{secrets.GITHUB_TOKEN}}
-        script: |            
-            github.projects.createCard({
-              column_id: process.env.PROJECT_COLUMN_ID,
-              content_id: context.payload.issue.id,
-              content_type: "Issue"
-            })