(maint) Decommission Azure
(maint) Decommission Azure

- LCOW is no longer a viable platform with differences worth testing on
  Windows. Windows containers have moved to WSL2 which is essentially a
  Ubuntu VM running Docker inside of it. There should be no important
  behavioral differences, and performance of bind mounts is apparently
  very slow.

  Azure was kept around while there were problems with TravisCI, but
  upon upgrading from 19.03 to 20.10+, the buildkit issues seem to have
  been resolved, so Travis can be relied on exclusively for now.

  Remove the job definition file and delete the job inside of Azure.

puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb,puppetlabs/puppetdb