Ease debugging BaselineNeonErrorFormatterIntegrationTest

[staabm]

I see this test fail more often on PRs lately with output like:

php vendor/bin/paratest --runner WrapperRunner --no-coverage --group exec
ParaTest v6.6.3 upon PHPUnit 9.6.20 by Sebastian Bergmann and contributors.

............................E...                                 32 / 32 (100%)

Time: 00:35.534, Memory: 80.00 MB

There was 1 error:

1) PHPStan\Command\ErrorFormatter\BaselineNeonErrorFormatterIntegrationTest::testRunUnixFileWithWindowsBaseline
PHPStan\ShouldNotHappenException: Could not clear result cache.

D:\a\phpstan-src\phpstan-src\tests\PHPStan\Command\ErrorFormatter\BaselineNeonErrorFormatterIntegrationTest.php:74
D:\a\phpstan-src\phpstan-src\tests\PHPStan\Command\ErrorFormatter\BaselineNeonErrorFormatterIntegrationTest.php:54

FAILURES!
Tests: 32, Assertions: 82, Errors: 1.
make: *** [Makefile:9: tests-integration] Error 2

lets see whether we can get a more meaningful output which might help to fix the underlying problem

[phpstan-bot]

This pull request has been marked as ready for review.