update planning_evaluator schema

Signed-off-by: t4-adc <grp-rd-1-adc-admin@tier4.jp>

Author: t4-adc

evaluator/autoware_planning_evaluator/schema/autoware_planning_evaluator.schema.json

@@ -6,11 +6,6 @@
     "autoware_planning_evaluator": {
       "type": "object",
       "properties": {
-        "output_metrics": {
-          "description": "If true, the evaluation node writes the metrics' statics to `<ros2_logging_directory>/autoware_metrics/<node_name>-<time_stamp>.json` when the node shut down,",
-          "type": "boolean",
-          "default": "false"
-        },
         "ego_frame": {
           "description": "reference frame of ego",
           "type": "string",