python3: bump to version 3.9.0

Refreshed patches.

Dropped 'patches-setuptools/004-site-patch.patch'
Does not apply anymore. Setuptools has removed site.py support:
   https://github.com/pypa/setuptools/issues/2165
If this is still needed, we may need to re-think it's implementation.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python/python3/patches-setuptools/004-site-patch.patch

@@ -1,14 +0,0 @@
---- a/setuptools/command/easy_install.py
-+++ b/setuptools/command/easy_install.py
-@@ -1324,7 +1324,10 @@ class easy_install(Command):
-             return  # already did it, or don't need to
- 
-         sitepy = os.path.join(self.install_dir, "site.py")
--        source = resource_string("setuptools", "site-patch.py")
-+        try:
-+            source = resource_string("setuptools", "site-patch.py")
-+        except FileNotFoundError:
-+            source = resource_string("setuptools", "site-patch.py.txt")
-         source = source.decode('utf-8')
-         current = ""
-