Remove :reliable tag from smoke tests

What does this MR do and why?

Describe in detail what your merge request does and why.

Removes :reliable tag from :smoke tests as it results in those tests being run twice in our smoke & reliable runs in MRs and as part of the release process. Marking a test as a smoke already implies that it is reliable otherwise it will block deployments.

See the discussion in https://gitlab.com/gitlab-org/quality/team-tasks/-/issues/1235#note_879190730

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