Move kernel repo configuration to deployment-all

Currently, kernel repositories are configured via Terraform.

To get rid of the whole machinery behind that, move it to gitlab-repo-config.

AC:

• extend gitlab-repo-config with any missing features: cki-tools!1177 (merged)
• archive https://gitlab.com/CentOS/automotive/src/kernel/kernel-automotive-9
• document that the repos are configured via GitOps, and link that in the project descriptions: i-d!436
• configure kernel repositories via deployment-all: d-a!2560
• retire terraform repo and associated tokens
• use branch configuration, default branch from rh-metadata
• configure cki-ci-bot via rh-metadata; the compose update machinery at https://gitlab.com/redhat/centos-stream/tests/kernel/kpet-db/-/blob/main/ystream_composes.yaml might need some update as well
• pull mirroring runs as a bot account instead of as @jwilsonrh, see e.g. mirror_user_id for rhel-9-sandbox
• monitoring for pull mirroring
• configure remaining kernel repos: kernel-ark

kernel-ark is tracked in kernel-ark#150