Azure Monitor: Fix typo that may cause an API request to fail (#88320)

Fix typo

public/app/plugins/datasource/azuremonitor/datasource.ts

@@ -164,7 +164,7 @@ export default class Datasource extends DataSourceWithBackend<AzureMonitorQuery,
   getMetricNamespaces(subscriptionId: string, resourceGroup?: string) {
     let url = `/subscriptions/${subscriptionId}`;
     if (resourceGroup) {
-      url += `/resourceGroups/${resourceGroup};`;
+      url += `/resourceGroups/${resourceGroup}`;
     }
     return this.azureMonitorDatasource.getMetricNamespaces({ resourceUri: url }, true);
   }