[devicelab] increase timeout for cull bench (#66481)

dev/benchmarks/macrobenchmarks/test_driver/cull_opacity_perf_test.dart

@@ -12,6 +12,6 @@ void main() {
     kCullOpacityRouteName,
     pageDelay: const Duration(seconds: 1),
     duration: const Duration(seconds: 10),
-    timeout: const Duration(seconds: 45),
+    timeout: const Duration(minutes: 2),
   );
 }