AutowireTrait and autowire for services behave differently for nullable types

I ran into this exact issue when dealing with an optional dependency. The suggested solution makes sense to me.

I added the test.

1) Drupal\KernelTests\Core\DependencyInjection\AutowireTest::testAutowireInvalidDependency
Symfony\Component\DependencyInjection\Exception\AutowiringFailedException: Cannot autowire service "Drupal\KernelTests\Core\DependencyInjection\InvalidServiceInterface": argument "$service" of method "Drupal\KernelTests\Core\DependencyInjection\InvalidOptionalDependencyController::_construct()", you should configure its value explicitly.
/builds/issue/drupal-3464426/core/lib/Drupal/Core/DependencyInjection/AutowireTrait.php:37
/builds/issue/drupal-3464426/core/tests/Drupal/KernelTests/Core/DependencyInjection/AutowireTest.php:191
ERRORS!
Tests: 4, Assertions: 7, Errors: 1.

Seems like good test coverage

I moved the test to be alongside where the exception is tested and I improved the test to check for more things.

Committed and pushed 8cd685b9f10 to 11.x and 86a448df9c8 to 11.2.x and 2f93f58bd14 to 10.6.x and fc389ed0fc6 to 10.5.x. Thanks!

Backporting to 10.5.x as a bugfix and I've run the tests there and everything is fine.