updating operator dashboard chart to be titled working instead of wokring (#6455)

### Describe Your Changes

Corrected spelling mistake in the operator json to be "working" instead
of "wokring"

### Checklist

The following checks are **mandatory**:

- [ x ] My change adheres [VictoriaMetrics contributing
guidelines](https://docs.victoriametrics.com/contributing/).

dashboards/operator.json

@@ -785,7 +785,7 @@
               "refId": "A"
             }
           ],
-          "title": "Wokring queue depth",
+          "title": "Working queue depth",
           "type": "timeseries"
         },
         {