bpo-32240: Add the const qualifier to declarations of PyObject* array arguments. (#4746)

diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index c7480a0..c8600a8 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -9835,7 +9835,7 @@
 }
 
 PyObject *
-_PyUnicode_JoinArray(PyObject *separator, PyObject **items, Py_ssize_t seqlen)
+_PyUnicode_JoinArray(PyObject *separator, PyObject *const *items, Py_ssize_t seqlen)
 {
     PyObject *res = NULL; /* the result */
     PyObject *sep = NULL;