Re-consider build dependency on tonistiigi/xx

[shaneutt]

We added a build tool for cross-compilation in https://github.com/kubernetes-sigs/blixt/pull/184:

https://github.com/kubernetes-sigs/blixt/blob/5428487fe560e05dac5eea7c7fd8d22d50388cd5/controlplane/Dockerfile#L1

This is a follow up on our previous conversation to make sure we don't forget to re-assess this dependency, and given it's place in the supply-chain decide definitively whether we need it or whether it would be straightforward to supply something ourselves.