bpo-46417: _curses uses PyStructSequence_NewType() (GH-30736)

The _curses module now creates its ncurses_version type as a heap
type using PyStructSequence_NewType(), rather than using a static
type.

* Move _PyStructSequence_FiniType() definition to pycore_structseq.h.
* test.pythoninfo: log curses.ncurses_version.

Python/thread.c

@@ -6,7 +6,8 @@
    Stuff shared by all thread_*.h files is collected here. */
 
 #include "Python.h"
-#include "pycore_pystate.h"   // _PyInterpreterState_GET()
+#include "pycore_pystate.h"       // _PyInterpreterState_GET()
+#include "pycore_structseq.h"     // _PyStructSequence_FiniType()
 
 #ifndef _POSIX_THREADS
 /* This means pthreads are not implemented in libc headers, hence the macro