python3: Fix compilation without deprecated APIs

This is based on upstream work here:

https://github.com/python/cpython/pull/3934
and
https://github.com/python/cpython/pull/39430

First patch was kept as is (just rebased) while the second was combined
into one.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

lang/python/python3/Makefile

@@ -14,7 +14,7 @@ PYTHON_VERSION:=$(PYTHON3_VERSION)
 PYTHON_VERSION_MICRO:=$(PYTHON3_VERSION_MICRO)
 
 PKG_NAME:=python3
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 PKG_VERSION:=$(PYTHON_VERSION).$(PYTHON_VERSION_MICRO)
 
 PKG_SOURCE:=Python-$(PKG_VERSION).tar.xz