Update tests to latest symfony/yaml

[cebe]

There was symfony/symfony#34805, which is finally fixed now. 🥳
That was failing the tests on Symfony YAML >=4.4 including all 5.x versions.

Now that one is fixed but with that fix there came symfony/symfony#39521 which breaks our tests in a different way 🙈 .
The fix of symfony/symfony#34805 and also break symfony/symfony#39521 came in 4.4.17, 5.1.9, 5.2.0.