Add TTFB threshold for the Single Issue API test
The MR adds TTFB threshold for the Single Issue Details API test. The test intermittently fails on 1k and 2k environment, the performance issue is raised gitlab-org/gitlab#326768.
The MR adds TTFB threshold for the Single Issue Details API test. The test intermittently fails on 1k and 2k environment, the performance issue is raised gitlab-org/gitlab#326768.