Merge branch '469514-remove-distributions-from-metric-and-event-definitions' into 'master'

Remove distributions from metric and event schemas

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/179438



Merged-by: Jonas Larsen <jlarsen@gitlab.com>
Approved-by: Jonas Larsen <jlarsen@gitlab.com>
Co-authored-by: Niko Belokolodov <nbelokolodov@gitlab.com>