feat: add renovate.json & mergify.yml

Signed-off-by: PoAn Yang <poan.yang@suse.com>
(cherry picked from commit f4a19bf)

.github/mergify.yml

@@ -0,0 +1,27 @@
+pull_request_rules:
+- name: Automatically merge Renovate PRs
+  conditions:
+  - check-success="Build ISO Images (x64)"
+  - check-success="Build ISO Images (arm64)"
+  - check-success="Build and deploy"
+  - author = renovate[bot]
+  actions:
+    merge:
+      method: rebase
+
+- name: Automatically approve Renovate PRs
+  conditions:
+  - check-success="Build ISO Images (x64)"
+  - check-success="Build ISO Images (arm64)"
+  - check-success="Build and deploy"
+  - author = renovate[bot]
+  actions:
+    review:
+      type: APPROVE
+
+- name: Ask to resolve conflict
+  conditions:
+  - conflict
+  actions:
+    comment:
+      message: This pull request is now in conflict. Could you fix it @{{author}}? 🙏

renovate.json

@@ -0,0 +1,5 @@
+{
+    "extends": [
+        "github>harvester/renovate:renovate-default"
+    ]
+}