Limit the displayed reports in test health issue comments while preserving the total count

Example: gitlab-org/gitlab#464150 (comment 1926306405)

This test health issue contains thousands of reports, causing request timeouts because the payload is too big. We should limit the number of historical reports we display

See log: https://log.gprd.gitlab.net/app/r/s/fURt9 (Need to adjust time frame to the past month)

Interestingly the errors only started since November 6.