chore: use iwyu on math/**.cpp

math/iterative_factorial.cpp

@@ -25,10 +25,10 @@
  *
  */
 
-#include <cassert>    /// for assert
-#include <cstdint>    /// for integral types
-#include <exception>  /// for std::invalid_argument
-#include <iostream>   /// for std::cout
+#include <cassert>    // for assert
+#include <cstdint>    // for uint64_t, uint8_t
+#include <iostream>   // for operator<<, basic_ostream, cout
+#include <stdexcept>  // for invalid_argument
 
 /**
  * @namespace