chore: add rebase github action

.github/workflows/rebase.yml

@@ -0,0 +1,25 @@
+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:
+            - uses: actions/checkout@master
+            - name: Automatic Rebase
+              uses: cirrus-actions/rebase@master
+              env:
+                  GITHUB_TOKEN: ${{ secrets.GH_PUSH_TOKEN }}
+
+    # https://github.community/t5/GitHub-Actions/Workflow-is-failing-if-no-job-can-be-ran-due-to-condition/m-p/38186#M3250
+    always_job:
+        name: Always run job
+        runs-on: ubuntu-latest
+        steps:
+            - name: Always run
+              run: echo "This job is used to prevent the workflow to fail when all other jobs are skipped."