Fix test failures against Drupal 11/PHP 8.3

The PHPStan problem is clear (Core added a method in 11.x, so the “this method doesn’t exist” warning won’t be displayed anymore), but the two test failures are a bit inexplicable:

1. I cannot reproduce the failure in ExcerptFieldTest, even though I’m using the exact same versions as GitLab CI. However, I remember that I already had a problem somewhere with \Drupal::state() in Functional tests in the CI, so at a hunch I changed the mechanism by which the test tells the alter hook to change the excerpt template used – and it worked indeed.
   There seems to be something broken in GitLab CI when using \Drupal::state() in Functional tests. (Pity I can’t remember anymore where I’ve seen this before, or howI solved it then.)
2. The failure in ViewsDisplayCachingTest I can reproduce, but not fully explain: it seems Core is to blame here, as AssertViewsCacheTagsTrait::assertViewsCacheTags() fails to sort both sets of cache tags before comparing them, leading to a bogus comparison failure. Just adding a single sort($build['#cache']['tags']); line fixes the problem. But in order to fix this here, we of course have to override the whole method.
   Not sure what’s going on here, it seems something changed in array comparisons between PHP 8.1 and 8.3? But no idea why Core wouldn’t have picked this up.

Anyways, I created an MR with an attempt at fixing the problems, but the solutions for the test failures are both a bit unsatisfactory, so not sure if I should merge this in its current form. Any help or feedback would be much appreciated!

The MR is indeed passing tests, but I think I’ll wait for feedback still a bit. Would be great to find proper fixes for those problems.

Update: mstrelan → pointed me to the Core issue 📌 sebastianbergmann/comparator:5.0.2 Introduces (for Drupal) breaking changes Fixed , which discusses the problem in AssertViewsCacheTagsTrait::assertViewsCacheTags(). So, apparently this will be fixed in Core, and we can just temporarily fix it in this module to make CI pass again.

Update 2: mstrelan → and catch → to the new caching for state introduced in Drupal 10.3 ( 📌 Use cache collector for state Needs review ) and apparently made the default behavior in Drupal 11 ( 📌 Remove state_cache setting in Drupal 11 Fixed ). So, we probably just need to work around that cache in ExcerptFieldTest.

drunken monkey → credited berdir → .

drunken monkey → credited catch → .

drunken monkey → credited mstrelan → .

Changed the ExcerptFieldTest fix to use a custom key-value store, as suggested. CI passes, so I merged.

Also, the Core issue ( 📌 sebastianbergmann/comparator:5.0.2 Introduces (for Drupal) breaking changes Fixed ) has been fixed, so once the MAX_PHP_VERSION test uses a Core version with that change included, we can get rid of our custom override to ViewsDisplayCachingTest::assertViewsCacheTags().
I created 📌 Remove our custom ViewsDisplayCachingTest::assertViewsCacheTags() override Postponed as a follow-up to do that.