bpo-3329: Fix typo in PyObjectArenaAllocator doc (GH-24795)

diff --git a/Doc/c-api/memory.rst b/Doc/c-api/memory.rst
index 588668e..d2d212b 100644
--- a/Doc/c-api/memory.rst
+++ b/Doc/c-api/memory.rst
@@ -555,7 +555,7 @@
    +--------------------------------------------------+---------------------------------------+
    | ``void* alloc(void *ctx, size_t size)``          | allocate an arena of size bytes       |
    +--------------------------------------------------+---------------------------------------+
-   | ``void free(void *ctx, size_t size, void *ptr)`` | free an arena                         |
+   | ``void free(void *ctx, void *ptr, size_t size)`` | free an arena                         |
    +--------------------------------------------------+---------------------------------------+
 
 .. c:function:: void PyObject_GetArenaAllocator(PyObjectArenaAllocator *allocator)