pythongh-131281: Add include for pystats builds (python#131369)

Add include to for pystats builds

Author: Fidget-Spinner

Python/specialize.c

@@ -18,6 +18,7 @@
 #include "pycore_opcode_utils.h"  // RESUME_AT_FUNC_START
 #include "pycore_pylifecycle.h"   // _PyOS_URandomNonblock()
 #include "pycore_runtime.h"       // _Py_ID()
+#include "pycore_unicodeobject.h" // _PyUnicodeASCIIIter_Type
 
 #include <stdlib.h> // rand()