Fix progress pill type check to ensure stages array is not empty before evaluation.

Author: Arpan-206

app/components/course-page/configure-extensions-modal/extension-card.ts

@@ -44,7 +44,7 @@ export default class ExtensionCard extends Component<Signature> {
 
   get progressPillType(): 'completed' | 'in_progress' | null {
     const stages = this.args.extension.sortedStages;
-    const allComplete = stages.every((stage) => this.args.repository.stageIsComplete(stage));
+    const allComplete = stages.length > 0 && stages.every((stage) => this.args.repository.stageIsComplete(stage));
     const currentStageInExtension = this.args.repository.currentStage && stages.includes(this.args.repository.currentStage);
 
     if (allComplete) return 'completed';