Rather than downloading the hash every time, we can record the hashes
for our well-known assets and bake them into the kOps binary. If the
hash is not baked in, we will continue to fall-back to downloading it,
this is important for new k8s versions, or where the user specifies a
version of one of our well-known assets (such as containerd).
We create some yaml files that record the hashes for well-known file assets,
and then we will be able to look them up by their canonical URL.
This is not yet actually used, that can be done in a future commit.