[toulouse][montcalm] Remove PSU metrics since we can't monitor them

IPMI metris that allow to monitor each power supply's electrical consumption are inconsistent.

Sometimes they return valid values, sometimes they return nothing.

Because this metric is buggy (and because it make the test_metrics fail), this merge request remove them.

data/grid5000/sites/toulouse/clusters/montcalm/montcalm.json

@@ -13,30 +13,6 @@
         "protocol": "ipmisensor"
       }
     },
-    {
-      "description": "Power consumption of Psu 1 reported by BMC, in watt",
-      "labels": {
-        "psu": "1"
-      },
-      "name": "bmc_psu_power_watt",
-      "period": 5000,
-      "source": {
-        "id": 68,
-        "protocol": "ipmisensor"
-      }
-    },
-    {
-      "description": "Power consumption of Psu 2 reported by BMC, in watt",
-      "labels": {
-        "psu": "2"
-      },
-      "name": "bmc_psu_power_watt",
-      "period": 5000,
-      "source": {
-        "id": 70,
-        "protocol": "ipmisensor"
-      }
-    },
     {
       "description": "Temperature reported by BMC, in celsius",
       "name": "bmc_ambient_temp_celsius",