make update-licenses is non-deterministic.
It seems to add or remove the version segments of the license URLs each time I run it.

Originally posted by @wallrj in #6601 (comment)

It was probably caused an incident at GitHub:

• https://www.githubstatus.com/incidents/pxg3dz4yg7lp

You can see the test-grid periodics failing at that same time:

• https://testgrid.k8s.io/cert-manager-presubmits-master#pull-cert-manager-master-license

In such circumstances make update-licenses should fail rather than print bad content to the LICENCE files.

/kind bug