[ACS-5287] Remove rebase workflow (#3217)

.github/workflows/rebase.yml

@@ -1,21 +0,0 @@
-name: Automatic Rebase
-
-on:
-  issue_comment:
-    types: [created]
-
-jobs:
-  rebase:
-    name: Rebase
-    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout the latest code
-        uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-
-      - name: Automatic Rebase
-        uses: cirrus-actions/rebase@1.3.1
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}