Entity recursive rendering protection is not compatible with Fibers

Coming here from #3583187-8: [random test failure] DuplicateContextualLinksTest::testSameContextualLinks:

However, while trying to do that, I discovered why this test suddenly started to fail so often, and it's because of #2940605: Can only intentionally re-render an entity with references 20 times. Since that issue, the node in our test is no longer being rendered in both views blocks, it now appears only the first block rendered on the page, which (funnily enough) is the _second_ views block, that's why my initial MR asserted that one :)

Not sure if these are the same issue, but can be investigated, and if not, we can open a separate issue.

I checked this change on the test that was failing randomly and it does fix it! Working on a test that doesn't require a view to trigger the problem.

Pushed the test! It was quite tricky to determine all the conditions required to hit this problem: we need a block that's placeholdered so it renders in a Fiber, and the entity being rendered needs a formatted text field to create filter placeholders that cause the Fiber to suspend mid-render, allowing the other block's Fiber to start and hit the collision.

Test-only pipeline fails as expected: https://git.drupalcode.org/project/drupal/-/jobs/9273587

Triaged and I didn't find anything amiss. I have updated credit.

Committed a2ee249 and pushed to main. Thanks!
Committed b8c65c4 and pushed to 11.x. Thanks!

Is the code in prior to #2940605: Can only intentionally re-render an entity with references 20 times also vulnerable to this? I'm not sure. I.e do we need to work on backporting a fix to 11.3.x for the different apporach to entity render recursion protection?

@taran2l that is great - thanks for testing so thoroughly and the early adoption - it is great to fix stuff before a stable release!