[4.3] Mark deprecation in DelegatingPsrLogger

[nikosdion]

See #39134 (comment)

Summary of Changes

\Joomla\CMS\Log\DelegatingPsrLogger was marked @internal and a deprecation notice information developers it will be marked final has been added.

Testing Instructions

None. This PR only changes the DocBlock.

Link to documentations

Please select:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org: PR 61

[wilsonge]

I'm probably being overly pedantic here but isn't this better off as a note rather than deprecated. Because people will still be able to init the class and it's not deprecated (in the short term anyhow) for that purpose?

[nikosdion]

The idea is that if someone does Whatever extends \Joomla\CMS\Log\DelegatingPsrLogger we want them to get the big strikethrough and warning in their IDE, hinting them that something is changing. Hopefully they will look at the core class and figure out what the deprecation is.

In the PR for 5.0 the deprecation is removed. The class is made final and the @internal mark is kept.

[HLeithner]

Thanks