Remove unused header file

Author: MatthiasReumann

mlir/lib/Dialect/QCO/Transforms/Mapping/Mapping.cpp

@@ -20,7 +20,6 @@
 #include <llvm/ADT/TypeSwitch.h>
 #include <llvm/Support/Debug.h>
 #include <llvm/Support/ErrorHandling.h>
-#include <mlir/Analysis/TopologicalSortUtils.h>
 #include <mlir/Dialect/Func/IR/FuncOps.h>
 #include <mlir/IR/Block.h>
 #include <mlir/IR/BuiltinOps.h>