[3.13] gh-140474: Fix memory leak in array.array (GH-140478) (GH-140499)

gh-140474: Fix memory leak in `array.array` (GH-140478)
(cherry picked from commit aa9d0a61d5)

Co-authored-by: Stan Ulbrych <89152624+StanFromIreland@users.noreply.github.com>

Modules/arraymodule.c

@@ -2806,6 +2806,9 @@ array_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
                         Py_SET_SIZE(self, n);
                         self->allocated = n;
                     }
+                    else {
+                        PyMem_Free(ustr);
+                    }
                 }
                 else { // c == 'w'
                     Py_ssize_t n = PyUnicode_GET_LENGTH(initial);