use new loki syntax

examples/dotnet/oats.yaml

@@ -17,6 +17,6 @@ expected:
     - promql: 'http_server_active_requests{http_request_method="GET"}'
       value: ">= 0"
   logs:
-    - logql: '{exporter="OTLP"} | json | body =~ `Anonymous player is rolling the dice.*`'
+    - logql: '{service_name="rolldice"} |~ `Anonymous player is rolling the dice.*`'
       contains:
         - 'Anonymous player is rolling the dice'