ci(gitlab-ci): Remove needs that cause invalid pipelines

This patch removes the needs relation since it requires all `parallel`
jobs to be executed before continuing, which break when only one helm
chart is linted.

Error message:
'chart-package: [keycloak]' job needs 'chart-helm-unittest: [mok]' job, but 'chart-helm-unittest: [mok]' is not in any previous stage