[neutron][all] No module named 'packaging.pylock' failures

Hi, Started seeing this failure yesterday in the neutron-functional job: ModuleNotFoundError: No module named 'packaging.pylock' Full ouptput at https://paste.opendev.org/show/bawqTgzkecxaK5DVEEAA/ I figured it was another issue with a new release of the packaging library as I see a 26.0 now, but upper-constraints is pinned to ==25.0 so I don't see how it's being pulled-in. The logs do show 26.0 being used at the end so I'm confused. I even tried to do a quick pin but it's still using 26.0: https://review.opendev.org/c/openstack/neutron/+/977556 Have any other projects seen this? Is 26.0 causing this or is it another interaction between libraries? Thanks for any help, -Brian