bpo-39943: Add the const qualifier to pointers on non-mutable PyUnicode data. (GH-19345)

diff --git a/Modules/_operator.c b/Modules/_operator.c
index 007c21b..19026b6 100644
--- a/Modules/_operator.c
+++ b/Modules/_operator.c
@@ -1170,7 +1170,7 @@
     for (idx = 0; idx < nattrs; ++idx) {
         PyObject *item = PyTuple_GET_ITEM(args, idx);
         Py_ssize_t item_len;
-        void *data;
+        const void *data;
         unsigned int kind;
         int dot_count;