Fix grammar in runner-related specs, views and localisations.

What does this MR do?

See https://gitlab.com/gitlab-org/gitlab-ce/issues/51357

This MR is the second of three that will correct the grammar of "setup" to "set up" project wide. This MR only touches files related to Runners, including views, specs and localisations.

Ported to EE in https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/7344 (please merge EE MR first)

Does this MR meet the acceptance criteria?

• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides