ci(mergify): remove post_check action (#552)

post_check action is apparently a premium/paid feature, Remove it from the config

.mergify.yml

@@ -1,19 +1,4 @@
 pull_request_rules:
-  - name: Conventional Commit
-    conditions:
-      - "title~=^(fix|feat|docs|style|refactor|perf|test|build|ci|chore|revert)(?:\\(.+\\))?:"
-    actions:
-      post_check:
-        title: |
-          {% if check_succeed %}
-          Title follows Conventional Commit
-          {% else %}
-          Title does not follow Conventional Commit
-          {% endif %}
-        summary: |
-          {% if not check_succeed %}
-          Your pull request title must follow [Conventional Commit](https://www.conventionalcommits.org/en/v1.0.0/).
-          {% endif %}
   - name: backport patches to v1 branch
     conditions:
       - base=main