fix: remove memory leak iterative_factorial.cpp (#2535)

* fix: remove memory leak

* tests: check properly if `math::iterativeFactorial` throws

math/iterative_factorial.cpp

@@ -46,7 +46,7 @@ namespace math {
  */
 uint64_t iterativeFactorial(uint8_t n) {
     if (n > 20) {
-        throw new std::invalid_argument("Maximum n value is 20");
+        throw std::invalid_argument("Maximum n value is 20");
     }
 
     // 1 because it is the identity number of multiplication.
@@ -101,12 +101,14 @@ static void test() {
     std::cout << "Exception test \n"
                  "Input: 21 \n"
                  "Expected output: Exception thrown \n";
+
+    bool wasExceptionThrown = false;
     try {
         math::iterativeFactorial(21);
-    } catch (std::invalid_argument* e) {
-        std::cout << "Exception thrown successfully \nContent: " << e->what()
-                  << "\n";
+    } catch (const std::invalid_argument&) {
+        wasExceptionThrown = true;
     }
+    assert(wasExceptionThrown);
 
     std::cout << "All tests have passed successfully.\n";
 }