Update allowed types for query/query_range keys in docs

Update docs to say that strings or numbers are allowed in the query and
query_range keys of metrics dashboards.

doc/operations/metrics/dashboards/yaml.md

@@ -89,8 +89,8 @@ is no longer used.
 | `id` | string | no | Used for associating dashboard metrics with database records. Must be unique across dashboard configuration files. Required for [alerting](../alerts.md) (support not yet enabled, see [relevant issue](https://gitlab.com/gitlab-org/gitlab/-/issues/27980)). |
 | `unit` | string | yes | Defines the unit of the query's return data. |
 | `label` | string | no, but highly encouraged | Defines the legend-label for the query. Should be unique within the panel's metrics. Can contain time series labels as interpolated variables. |
-| `query` | string | yes if `query_range` is not defined | Defines the Prometheus query to be used to populate the chart/panel. If defined, the `query` endpoint of the [Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/) will be utilized. |
-| `query_range` | string | yes if `query` is not defined | Defines the Prometheus query to be used to populate the chart/panel. If defined, the `query_range` endpoint of the [Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/) will be utilized. |
+| `query` | string/number | yes if `query_range` is not defined | Defines the Prometheus query to be used to populate the chart/panel. If defined, the `query` endpoint of the [Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/) will be utilized. |
+| `query_range` | string/number | yes if `query` is not defined | Defines the Prometheus query to be used to populate the chart/panel. If defined, the `query_range` endpoint of the [Prometheus API](https://prometheus.io/docs/prometheus/latest/querying/api/) will be utilized. |
 | `step` | number | no, value is calculated if not defined | Defines query resolution step width in float number of seconds. Metrics on the same panel should use the same `step` value. |
 
 ## Dynamic labels