Add missing include to benchmark/catch_execution_plan.hpp

Fixes #2275

src/catch2/benchmark/catch_execution_plan.hpp

@@ -18,6 +18,7 @@
 #include <catch2/benchmark/detail/catch_run_for_at_least.hpp>
 
 #include <algorithm>
+#include <iterator>
 
 namespace Catch {
     namespace Benchmark {