Upgrade to setuptools 61.1.0

This fixes Python 3.10 compat, but does remove Python2 compat.

Test: treehugger
Change-Id: I8e19ad8dec6b34482bfbe996413d3f793ada276c
diff --git a/_distutils_hack/override.py b/_distutils_hack/override.py
new file mode 100644
index 0000000..2cc433a
--- /dev/null
+++ b/_distutils_hack/override.py
@@ -0,0 +1 @@
+__import__('_distutils_hack').do_override()