Update prometheusmetrics.md (opensearch-project#7561)

Fixed a broken image link on https://opensearch.org/docs/latest/observing-your-data/prometheusmetrics/

Signed-off-by: Heather Halter <HDHALTER@AMAZON.COM>

_observing-your-data/prometheusmetrics.md

@@ -163,7 +163,7 @@ You can view metrics from remote OpenSearch clusters by using the **Metrics** to
 
 You can also view metric visualizations from other sources alongside local metric visualizations. From the **DATA SOURCES** dropdown menu, choose the remote metric visualization to add it to the group of visualizations already shown on the dashboard. An example dashboard is shown in the following image.
 
-<img src="{site.url}}{{site.baseurl}}/images/metrics/otel-metrics-remote-cluster-selection.png" alt="Metrics dashboard" width="700"/>
+<img src="{{site.url}}{{site.baseurl}}/images/metrics/otel-metrics-remote-cluster-selection.png" alt="Metrics dashboard" width="700"/>
 
 To learn about multi-cluster support for data sources, see [Enable OpenSearch Dashboards to support multiple OpenSearch clusters](https://github.com/opensearch-project/OpenSearch-Dashboards/issues/1388).