Merge branch 'sh-drop-re2-diagnostic' into 'main'

Drop RE2 diagnostic

See merge request https://gitlab.com/gitlab-org/gitlab-development-kit/-/merge_requests/3883



Merged-by: Nao Hashizume <nhashizume@gitlab.com>
Approved-by: Nao Hashizume <nhashizume@gitlab.com>
Co-authored-by: Stan Hu <stanhu@gmail.com>