Allow KUBECONFIG and GITLAB_CI env in integration tests
What does this MR do?
Without these variables k3s tests can't run export GITLAB_CI due to http://gitlab.com/gitlab-org/gitlab-runner/blob/ac7a05af1b4b619094e0927285a44457e473817e/executors/kubernetes/kubernetes_integration_test.go#L435-435
Why was this MR needed?
What's the best way to test this MR?
What are the relevant issue numbers?
Related to #28009 (closed)
Edited by Georgi N. Georgiev