ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR: duplicate key value violates unique constraint "index_ci_pipeline_sc...

https://sentry.gitlab.net/gitlab/gitlabcom/issues/2448382/?referrer=gitlab_plugin

PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "index_ci_pipeline_schedule_variables_on_schedule_id_and_key"
DETAIL:  Key (pipeline_schedule_id, key)=(90380, FOO1) already exists.

  active_record/connection_adapters/postgresql_adapter.rb:675:in `exec_params'
    @connection.exec_params(sql, type_casted_binds)
  active_support/concurrency/load_interlock_aware_monitor.rb:21:in `handle_interrupt'
    Thread.handle_interrupt(EXCEPTION_NEVER) do
  active_support/concurrency/load_interlock_aware_monitor.rb:21:in `synchronize'
    Thread.handle_interrupt(EXCEPTION_NEVER) do
  active_record/connection_adapters/abstract_adapter.rb:721:in `block in log'
    @lock.synchronize do
  active_support/notifications/instrumenter.rb:24:in `instrument'
    yield payload if block_given?
...
(245 additional frame(s) were not displayed)

ActiveRecord::RecordNotUnique: PG::UniqueViolation: ERROR:  duplicate key value violates unique constraint "index_ci_pipeline_schedule_variables_on_schedule_id_and_key"
DETAIL:  Key (pipeline_schedule_id, key)=(90380, FOO1) already exists.