Enable python3 jobs for git-upstream
Enable python3 jobs for git-upstream

Ensure python3 compatibility is retained.

Change-Id: I2767cec42e3b41d15ecfa2810c878ecd68937e57
Depends-On: I51617a433987d1549e0686c1feda01f971b13fa0

openstack-infra/project-config,Tesora/tesora-project-config,openstack-infra/project-config,Tesora/tesora-project-config,dongwenjuan/project-config,dongwenjuan/project-config