chore: use iwyu on graph/**.cpp

graph/dijkstra.cpp

@@ -23,13 +23,14 @@
  * at the code below to understand in better way.
  *
  */
-#include <cassert>
-#include <iostream>
-#include <limits>
-#include <memory>
-#include <queue>
-#include <utility>
-#include <vector>
+#include <stdint.h>    // for int64_t
+#include <cassert>     // for assert
+#include <iostream>    // for basic_ostream, char_traits, operator<<, basic_...
+#include <limits>      // for numeric_limits
+#include <queue>       // for priority_queue
+#include <utility>     // for pair, make_pair
+#include <vector>      // for vector
+#include <functional>  // for greater
 
 constexpr int64_t INF = std::numeric_limits<int64_t>::max();