Runs every handler registered for the firing trigger's expression.

Handlers run to settlement — all of them are awaited even when some reject, so one failing handler never abandons the others. After every handler has settled, a rejection is REPORTED and then PROPAGATED as an AggregateError, and a firing expression with no registered handler throws: createScheduledHandler is a bare delegation, so the platform's own response — counting the whole invocation as failed — becomes the sink that needs no logger configuration (M70l X9-5). Breaking vs earlier versions, where dispatch never rejected; an application that wants the old fire-and-forget behaviour wraps its handlers in try.