Codify the creation of test containers

[portersrc]

Not ready for review. Placeholder for CI meeting on Oct 9, 2024.

Meant as a starting point to address:
kata-containers/kata-containers#9360

Some points for initial discussion:

1. Do we really (really) want to put this in operator, or is infra ok?
2. CoCo packages is not well organized. Can we have a naming scheme for these new images? It would also help avoid collisions while we work through all existing test cases that use these images.
3. There may be requirements from the github maintainers to set some stuff, e.g. secrets.COSIGN_PASSWORD. Alternatively, these are just tests, so we can just use regular strings.

[stevenhorsman]

Triggering suggestion

[stevenhorsman]

Could we add the option to manually trigger them? e.g. if we might want to re-gen them to check the e2e process is still working? Also we might only want to run this automatically if a related file changes if we end up using this repo for other thing?

Suggested change

	on: [push]
	on:
	workflow_dispatch:
	push:
	branches:
	- 'main'
	paths:
	- 'container-images'
	- '.github/workflows/build-test-containers.yaml'