chore: use iwyu on sorting/**.cpp

sorting/dnf_sort.cpp

@@ -10,11 +10,13 @@
  * @author [Sujal Gupta](https://github.com/heysujal)
  */
 
-#include <algorithm>  /// for std::is_sorted
-#include <cassert>    /// for assert
-#include <cstdint>    /// for integral typedefs
-#include <iostream>   /// for std::swap and io operations
-#include <vector>     /// for std::vector
+#include <algorithm>  // for is_sorted
+#include <cassert>    // for assert
+#include <cstdint>    // for uint64_t
+#include <iostream>   // for basic_ostream, operator<<, char_traits, cout, endl
+#include <vector>     // for vector
+#include <iterator>   // for begin, end
+#include <utility>    // for swap
 
 /**
  * @namespace sorting