Add oci cache spegel as default feature for wan bandwidth saving

[usrbinkat]

https://spegel.dev/docs/getting-started/

thank you @ringods

[phillebaba]

@usrbinkat Out if interest are you looking to leverage Spegel outside of Kubernetes, or is the plan to run it inside Kubernetes?

I tried to dig a bit into Kargo to understand the architecture a bit better. I am still new to the project so please forgive my ignorance 😄

[usrbinkat]

@phillebaba great question. I'd like to add a helm release as a module similar to how cilium is installed via helm with the goal of reducing load on WAN especially since Kargo is all about the qemu2 disk distribution via oci and spegel seems to reduce duplicate pulls which would be very helpful.

EDIT: something like this but for spegel https://github.com/ContainerCraft/Kargo/blob/main/pulumi/src/cilium/deploy.py