Updated Mergify config

Author: mmhat

.mergify.yml

@@ -4,6 +4,8 @@ queue_rules:
       # See https://docs.mergify.io/conditions/#validating-all-status-checks
       - 'check-success~=.* on ubuntu-latest'
       - 'check-success~=.* on windows-latest'
+    merge_method: squash
+
 pull_request_rules:
   - name: 'Automatically merge pull requests'
     conditions:
@@ -13,9 +15,9 @@ pull_request_rules:
     actions:
       queue:
         name: default
-        method: squash
+
   - name: 'Delete head branch after merge'
     conditions:
-      - merged
+      - 'merged'
     actions:
       delete_head_branch: {}