Doctrinebundle: [Entity Listeners] always lazy load via ServiceLocator

[dmaicher]

Since soon support for Symfony < 3.4 will be dropped we could use a ServiceLocator here

https://github.com/doctrine/DoctrineBundle/blob/master/Mapping/ContainerAwareEntityListenerResolver.php#L20

to and get rid of the lazy attribute completely?

https://github.com/doctrine/DoctrineBundle/blob/master/DependencyInjection/Compiler/EntityListenerPass.php#L44

So we don't have to mark the listeners public anymore and we can always lazily fetch them.

Or is there any reason to not always lazy load them?

[alcaeus]

We're working on dropping support for anything < 3.4 in #892, so I'll check that out before finalising the PR.

[alcaeus]

Just a heads up, I've decided to leave this out from #892 but will be changing this in time for a 1.11 release so we can deprecate the original behaviour. I just need some more time to wrap my head around the logic.

[dmaicher]

Looking into this now at EUFOSSA hackathon :+1:

[alcaeus]

Closing as #951 was merged 🎉