update python runtime of kinesis metrics yaml

Author: himsharma01

kinesis-firehose-cloudwatch-collection/metrics/KinesisFirehoseCWMetrics.template.yaml

@@ -407,7 +407,7 @@ Resources:
                   print(e)
                   cfnresponse.send(event, context, cfnresponse.FAILED, {"Error": str(e)}, physical_id)
               cfnresponse.send(event, context, cfnresponse.SUCCESS, response_data, physical_id)
-      Runtime: python3.7
+      Runtime: python3.11
       Timeout: 300
       Role: !GetAtt KinesisMetricsCloudWatchMetricsStreamLambdaRole.Arn