Fix PHPStan missingType.generics for FieldItemListInterface not specifying its type

phpstan-drupal has a stub that defines FieldItemListInterface as a generic, so we need to pass the type in the PHPDocs here.

See https://github.com/mglaman/phpstan-drupal/blob/main/stubs/Drupal/Core/Fi...

TBH I think it’s nonsense to have core lacking appropriate PHPDoc, for drupal-phpstan to write a stub gapfill, and then that gapfill to force back core implementations’ PHPDocs to be adjusted…

I would suggest to move the definitions in the stub from drupal-php to core as part of this issue.

phpstan-drupal uses a stub provider, so we can fix here and back port anything to phpstan-drupal and use a version check on Drupal to decide if the phpstan-drupal stub should be loaded or not

Done #7 for the Drupal core part (I think).

Left a comment on the MR but leaving in review for someone more familiar

Thanks for the response @mglaman. Moving to NW for rebase.

If you are another contributor eager to jump in, please allow the original poster @mglaman or @mondrake at least 48 hours to respond to feedback first, so they have the opportunity to finish what they started!

Rebased, only merge conflicts resolved.

Rebase seems good.

merge conflict

merged with 11.x, no conflicts. Dunno why GitLab still reports a merge error.

I'm really not sure about using templates like this. I realise I'm in the minority using vim (and without whatever vim support would take advantage of this, there's probably something somewhere), but don't think I'm the only one. There's also reading docs on api.drupal.org or gitlab which people sometimes do.

appears to need a rebase

If you are another contributor eager to jump in, please allow the previous poster at least 48 hours to respond to feedback first, so they have the opportunity to finish what they started!

The weirdness here is that this MR is practically just a c/p of (some of) the stubs that are defined in mglaman/phpstan-drupal. The difference is the use of FQCN as per Drupal code standards vs class names and use imports.

If we don't do this, Drupal core is not compatible with its own PHPStan tooling. Therefore we should remove the stubs from mglaman/phpstan-drupal if we aim at clearing the baseline... fun.

Appears some feedback was added to the MR.