fix(balatrobench): extraction of the keys for used_vouchers

Author: S1M0N38

.gitignore

@@ -251,3 +251,4 @@ benchmarks-old
 runs
 !tests/fixtures/runs/
 scripts
+runs-old

src/balatrobench/analyzer.py

@@ -42,7 +42,10 @@ def _read_used_vouchers(run_dir: Path) -> set[str]:
         last_line = line
 
     data = json.loads(last_line)
-    return set(data.get("used_vouchers", {}).keys())
+    used_vouchers = data.get("used_vouchers", [])
+    if isinstance(used_vouchers, dict):
+        used_vouchers = list(used_vouchers.keys())
+    return set(used_vouchers)
 
 
 class BenchmarkAnalyzer: