Add missing string for already_configured in GIOS integration (#30590)

homeassistant/components/gios/strings.json

@@ -15,6 +15,9 @@
       "wrong_station_id": "ID of the measuring station is not correct.",
       "invalid_sensors_data": "Invalid sensors' data for this measuring station.",
       "cannot_connect": "Cannot connect to the GIOŚ server."
+    },
+    "abort": {
+      "already_configured": "GIOŚ integration for this measuring station is already configured."
     }
   }
 }