Fix selection of a single scenario

dashboard/new-dashboard/src/components/common/PerformanceMetric.vue

@@ -50,7 +50,7 @@
         class="flex flex-1 flex-col gap-6 overflow-hidden"
       >
         <template
-          v-for="scenario in scenarioConfigurator.selected.value"
+          v-for="scenario in scenarios"
           :key="scenario"
         >
           <GroupProjectsChart
@@ -66,7 +66,7 @@
 </template>
 
 <script setup lang="ts">
-import { provide, ref } from "vue"
+import { computed, provide, ref } from "vue"
 import { useRouter } from "vue-router"
 import { AccidentsConfiguratorForTests } from "../../configurators/AccidentsConfigurator"
 import { createBranchConfigurator } from "../../configurators/BranchConfigurator"
@@ -147,6 +147,14 @@ const configurators: DataQueryConfigurator[] = [branchConfigurator, machineConfi
 
 provide(dashboardConfiguratorsKey, configurators)
 
+const scenarios = computed(() => {
+  if (scenarioConfigurator.selected.value == null) return []
+  if (Array.isArray(scenarioConfigurator.selected.value)) {
+    return scenarioConfigurator.selected.value
+  }
+  return [scenarioConfigurator.selected.value]
+})
+
 const releaseConfigurator = props.withInstaller ? new ReleaseNightlyConfigurator(persistentStateManager) : null
 if (releaseConfigurator != null) {
   configurators.push(releaseConfigurator)