Update docs examples to show configuring and injecting the attribute reader to listeners

[mbabker]

The documentation right now only covers injecting an annotation reader into the various event listener classes. With Symfony 6.4 deprecating the @annotation_reader service and 7.0 fully removing it, that makes this bit of the documentation less than optimal.

Additionally, the internal feature detection code in this package still heavily favors annotations over attributes, meaning if doctrine/annotations is installed in a project for any reason at all, the feature detection code is going to use annotations. This is less than optimal for applications using attributes, but not really actionable until a new major release is cut.

This PR updates the documentation to provide examples for injecting the attribute reader instead of an annotation reader in the IpTraceable and Symfony docs pages, as these pages do have some explicit Symfony config examples with setAnnotationReader calls configured; this can help users set up their environments more efficiently if they aren't using StofDoctrineExtensionsBundle (and for those who are, a resolution for stof/StofDoctrineExtensionsBundle#481 helps those folks).

Fixes #2780

[franmomu]

thanks @mbabker!