The C-API documentation introduction contains an error:

"Almost all Python objects live on the
heap: you never declare an automatic or static variable of type
:c:type:`PyObject`, only pointer variables of type :c:type:`PyObject*` can  be
declared.  The sole exception are the type objects; since these must never be
deallocated, they are typically static :c:type:`PyTypeObject` objects."

With heap types, PyTypeObject can be deallocated.