Merge branch 'mappelman/downstream-trigger-gob-e2e' into 'master'

Add downstream observability e2e trigger to ci

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/140746



Merged-by: Rémy Coutable <remy@rymai.me>
Approved-by: Rémy Coutable <remy@rymai.me>
Reviewed-by: Rémy Coutable <remy@rymai.me>
Reviewed-by: Nao Hashizume <nhashizume@gitlab.com>
Co-authored-by: Mat Appelman <mappelman@gitlab.com>