nose: clean up, support Python 3.10. (#8825)

Due to changes in setuptools, we need to run 2to3 ourselves.
While we're at it, lets apply relevant patches from Debian.

https://salsa.debian.org/python-team/packages/nose/

dev-python/nose/patches/debian/no-distribute_setup.diff

@@ -0,0 +1,28 @@
+From: Stefano Rivera <stefanor@debian.org>
+Date: Thu, 8 Oct 2015 10:01:59 -0700
+Subject: Don't even think about using distribute_setup to download things
+ during build
+
+Forwarded: not-needed
+Last-Update: 2012-02-03
+---
+ setup.py | 6 +-----
+ 1 file changed, 1 insertion(+), 5 deletions(-)
+
+diff --git a/setup.py b/setup.py
+index a710b30..765b7ae 100644
+--- a/setup.py
++++ b/setup.py
+@@ -7,11 +7,7 @@ py_vers_tag = '-%s.%s' % sys.version_info[:2]
+ test_dirs = ['functional_tests', 'unit_tests', os.path.join('doc','doc_tests'), 'nose']
+ 
+ if sys.version_info >= (3,):
+-    try:
+-        import setuptools
+-    except ImportError:
+-        from distribute_setup import use_setuptools
+-        use_setuptools()
++    import setuptools
+ 
+     extra = {'use_2to3': True,
+              'test_dirs': test_dirs,