add runners tolerations to register process
What does this MR do?
This MR makes it possible to add tolerations to the runner while the registration process.
Why was this MR needed?
In our k8s cluster the CI nodes have multiple taints. According to the gitlab-ci code only one tolerations can be added via the environment variable KUBERNETES_NODE_TOLERATIONS. so we need to add it to the registration process
Edited by Steve Xuereb