chore(mergify): Update config to use merge queue

Author: christopherthielen

.mergify.yml

@@ -6,16 +6,16 @@ pull_request_rules:
       - 'label=ready to squash and merge'
     actions:
       delete_head_branch: {}
-      merge:
+      queue:
         method: squash
-        strict: smart
+        name: default
   - name: Auto Rebase and Merge
     conditions:
       - base=master
       - status-success=ci
       - 'label=ready to rebase and merge'
     actions:
       delete_head_branch: {}
-      merge:
+      queue:
         method: rebase
-        strict: smart
+        name: default