[feature] Pre-cached images

[ArcherSeven]

Problem Description

We need a way to load a Talos image that has all of our custom and third party container images pre-loaded onto our machines before shipping to site so that we can assign those machines to clusters on site with as little bandwidth usage as possible.

Solution

Imagefactory, when run within our cloud, could generate an instance-specific talos image that contains a container image cache containing our needed images.

Alternative Solutions

A separate utility could write the cache to disk after the talos image has already been written. But this would probably be both harder to handle and more work to implement.

Notes

Attempting to track here a request that has been widely discussed previously.

[rsmitty]

This will be implemented as siderolabs/talos#9610. Will close this issue in favor of that one.