fix: bail if user cancels in ensureRepositoryExists

Author: JoshuaKGoldberg

Diff for: src/shared/options/ensureRepositoryExists.ts

@@ -52,6 +52,7 @@ export async function ensureRepositoryExists(
 		createRepository = false;
 
 		switch (selection) {
+			case undefined:
 			case "bail":
 				return {};