bpo-46417: Finalize structseq types at exit (GH-30645)

Add _PyStructSequence_FiniType() and _PyStaticType_Dealloc()
functions to finalize a structseq static type in Py_Finalize().
Currrently, these functions do nothing if Python is built in release
mode.

Clear static types:

* AsyncGenHooksType: sys.set_asyncgen_hooks()
* FlagsType: sys.flags
* FloatInfoType: sys.float_info
* Hash_InfoType: sys.hash_info
* Int_InfoType: sys.int_info
* ThreadInfoType: sys.thread_info
* UnraisableHookArgsType: sys.unraisablehook
* VersionInfoType: sys.version
* WindowsVersionType: sys.getwindowsversion()

Include/internal/pycore_pyerrors.h

@@ -12,6 +12,7 @@ extern "C" {
 /* runtime lifecycle */
 
 extern PyStatus _PyErr_InitTypes(PyInterpreterState *);
+extern void _PyErr_FiniTypes(PyInterpreterState *);
 
 
 /* other API */