Update hacking for Focal

As per victoria cycle testing runtime and community goal[1]
we need to migrate upstream CI/CD to Ubuntu Focal(20.04).

This bumps hacking to 3.2.0 in order to work with focal, disabling W504
to align with neutron (W503 is enabled in this version)

Story: #2007865
Task: #40199

[1] https://governance.openstack.org/tc/goals/selected/victoria/migrate-ci-cd-jobs-to-ubuntu-focal.html

Change-Id: Ic7a6da941172aae6dc504eb377c3e94de4805a89
5 files changed