ci: add action to retest failed approved PR's

Adding github action to retest the failed
approved PR's. sample output is available
at https://github.com/Madhu-1/retest-action/pull/3

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

.github/workflows/retest.yml

@@ -0,0 +1,18 @@
+---
+name: "Retest approved pull Requests"
+# yamllint disable-line rule:truthy
+on:
+  schedule:
+    # Run the retest action every 30 minutes
+    - cron: "30 * * * *"
+jobs:
+  retest:
+    runs-on: ubuntu-latest
+    steps:
+      # path to the retest action
+      - uses: ceph/ceph-csi/actions/retest@devel
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          required-label: "ci/retry/e2e"
+          max-retry: "5"
+          required-approve-count: "2"