terraform/jenkins-controller: add static builders

[flokli]

This adds builder.vedenemo.dev and hetzarm.vedenemo.dev as static builders to /etc/nix/machines, as well as the keyscan machinery.

#171 already ensured that ssh key works.

maxJobs is set to the number of cores the system sees, and speedFactor is set to 3, making it more attractive than the other builders.

[henrirosten]

@joinemm commented offline that the current version would add the remote builders to 'prod' environment too.
In 'prod' the /etc/secrets/remote-build-ssh-key would not be able to access the added external remote builders (which is what we want).

However, it might still be better to conditionalize the usage of these external remote builders on the envtype only for the 'priv' and 'dev' environments under the environment-specific options:

ghaf-infra/terraform/main.tf

Line 97 in d8d62be

opts = {

[flokli]

Updated, it's now conditionalized on (var.envtype == "dev" || var.envtype == "priv"). PTAL.

[henrirosten]

We might actually want to set the num_builders to 0 on 'priv' and 'dev' configurations either as part of this PR, or on a follow-up PR.

[flokli]

Let's do it in a followup, it's unrelated to adding static builders (what this PR does)