ci(mergify): upgrade configuration to current format (#345)

* ci(mergify): upgrade configuration to current format

* Clean up mergify configuration update

---------

Co-authored-by: Mergify <37929162+mergify[bot]@users.noreply.github.com>
Co-authored-by: Daniel Flores <daflogar@amazon.com>

Author: mergify[bot]

.mergify.yml

@@ -1,9 +1,10 @@
 queue_rules:
   - name: default
-    conditions:
-    # Conditions to get out of the queue (= merged)
+    merge_conditions:
+      # Conditions to get out of the queue (= merged)
       - status-success=Run Unit Tests
       - status-success=Semantic Pull Request
+    merge_method: squash
 
 pull_request_rules:
   - name: Automatically merge on CI success and review approval
@@ -21,7 +22,6 @@ pull_request_rules:
       - author!=dependabot[bot]
     actions:
       queue:
-        method: squash
         name: default
 
   - name: Automatically approve and merge Dependabot PRs
@@ -38,5 +38,4 @@ pull_request_rules:
       review:
         type: APPROVE
       queue:
-        method: squash
-        name: default
+        name: default