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()

Python/errors.c

@@ -1241,6 +1241,17 @@ _PyErr_InitTypes(PyInterpreterState *interp)
 }
 
 
+void
+_PyErr_FiniTypes(PyInterpreterState *interp)
+{
+    if (!_Py_IsMainInterpreter(interp)) {
+        return;
+    }
+
+    _PyStructSequence_FiniType(&UnraisableHookArgsType);
+}
+
+
 static PyObject *
 make_unraisable_hook_args(PyThreadState *tstate, PyObject *exc_type,
                           PyObject *exc_value, PyObject *exc_tb,