gh-129354: Use PyErr_FormatUnraisable() function (#129511)

Replace PyErr_WriteUnraisable() with PyErr_FormatUnraisable().

Objects/unicodeobject.c

@@ -1735,7 +1735,9 @@ unicode_dealloc(PyObject *unicode)
             PyObject *popped;
             int r = PyDict_Pop(interned, unicode, &popped);
             if (r == -1) {
-                PyErr_WriteUnraisable(unicode);
+                PyErr_FormatUnraisable("Exception ignored while "
+                                       "removing an interned string %R",
+                                       unicode);
                 // We don't know what happened to the string. It's probably
                 // best to leak it:
                 // - if it was popped, there are no more references to it