…d (weaverryan)This PR was merged into the 4.3-dev branch.Discussion----------Dispatching two events when a message is sent & handled| Q             | A| ------------- | ---| Branch?       | master| Bug fix?      | no| New feature?  | yes| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes| Fixed tickets | none| License       | MIT| Doc PR        | TODOAlternative to#30646. This uses a more generic system, so you could do anything when a message is sent. The main use-case is when a message is dispatched by a 3rd party.I didn't try to add *exhaustive* events everywhere: I added an event for a very specific use-case:When a message is dispatched by a 3rd party, being able to add stamps (e.g. `DelayStamp` or a future `AmqpRoutingKeyStamp` before the message is sent. Example:```phpclass MailerMessageSendToTransportEventSubscriber implements EventSubscriberInterface{    public function onSendMessage(SendMessageToTransportsEvent $event)    {        $envelope = $event->getEnvelope();        if (!$envelope->getMessage() instanceof SomeMailerMessage) {            return;        }        $event->setEnvelope($envelope->with(new AmpqRoutingKeyStamp('mailer-route')));    }    public static function getSubscribedEvents()    {        return [SendMessageToTransportsEvent::class => 'onSendMessage'];    }}```Along with#30557, we will now have the following events, regarding async messages:* Event when a message is sent to transports (this PR)* Event when a message is received from transport, but before handling it* Event when a message is received from transport and after handling itCommits-------a7ad1b4 Dispatching two events when a message is sent & handled

This PR was merged into the 7.4 branch.Discussion----------[Messenger] Simplify code| Q             | A| ------------- | ---| Branch?       | 7.4| Bug fix?      | no| New feature?  | no| Deprecations? | no| Issues        | -| License       | MITNoticed while working on#61843.There's no reason for the event to be dispatched inside the loop anymore:1. The event was [originally dispatched outside the loop](#30650).2. It was later [moved inside the loop](#30676) because of the retry mechanism.3. [The retry mechanism was later extracted](#34185), so there's no longer a need for the event to be dispatched inside the loop.Commits-------beeb4b9 [Messenger] Simplify code