Import attempt via Configuration Synchronization UI fails with a fatal error

Hey @mxh good to see you around here and thanks for the bug report and its fix. Looks like some tests are failing, though.

As for the 2.1.x branch, this seems to be the case for which you were already testing NULL !== parent::class, so it sounds like Phpstan is just being to picky here and I'd be OK to just ignore that line by adding // @phpstan-ignore-next-line. If we can resolve this that way, I would actually include that into a new release for 2.1 and 2.0 as I was just in the middle of preparing that release.

As for the 1.1 branch it looks like we have a more serious problem which may result from some core changes that we haven't tested against for ages. This may take a little longer to resolve.

@mxh is this still NW? If so, I'm going ahead and tag new releases without this for now, it doesn't seem to be a widespread issue so including that next time is probably sufficient?

I don't see anything else I can do to make PHPStan happy. Writing a test that tries to serialize and de-serialize an ECA config entity might help but I don't have time to do it. Using the currently provided fix as a patch and will see how it goes. Seems to be sufficient being addressed later on.

I've fixed the tests. For 2.1.x and 2.0.x I've instructed Phpstan to ignore that single line in the Trait as we know that it's certainly wrong in this scenario. For 1.1.x I've adjusted the CI settings so that we only test against Drupal 10, not 11.

Merged into 2.1.x and 1.1.x, and also back ported to 2.0.x