Remove issue management bot for now (#3472)

.github/workflows/issue-management.yml

@@ -1,16 +0,0 @@
-name: Issue Management
-on:
-  issues:
-    types: [opened, closed, reopened]
-  issue_comment:
-    types: [created]
-
-jobs:
-  issue-management:
-    name: Issue Management
-    runs-on: ubuntu-latest
-    steps:
-      - name: Issue Management
-        uses: mheap/github-action-issue-management@v1
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}