ci: add support for trio in Mergify automerge (#470)

Change-Id: Idc6ec012cceae67ceb11914763350b34addcce5e

Author: jd

.mergify.yml

@@ -14,7 +14,7 @@ queue_rules:
       - "check-success=test (3.9, py39)"
       - "check-success=test (3.10, py310)"
       - "check-success=test (3.11, py311)"
-      - "check-success=test (3.12, py312)"
+      - "check-success=test (3.12, py312,py312-trio)"
       - "check-success=test (3.12, pep8)"
 
 pull_request_rules: