chore: allow releases on previous major versions

owlbot.py

diff --git a/owlbot.py b/owlbot.py
index 1c2710f..60ef1dc 100644
--- a/owlbot.py
+++ b/owlbot.py
@@ -43,3 +43,5 @@
 # ----------------------------------------------------------------------------
 
 python.py_samples(skip_readmes=True)
+
+python.configure_previous_major_version_branches()