composer: allow PHP8

tests/nested.phpt

@@ -4,7 +4,6 @@ namespace Grifart\SuppressedExceptions\__tests;
 
 use Grifart\SuppressedExceptions\SuppressedExceptions;
 use Grifart\SuppressedExceptions\WithSuppressedExceptions;
-use Symfony\Component\Console\Exception\RuntimeException;
 use Tester\Assert;
 
 require __DIR__ . '/bootstrap.php';
@@ -15,9 +14,9 @@ class TestingSuppressedExceptionsException extends \RuntimeException implements
 
 }
 
-$previous = new TestingSuppressedExceptionsException('previous', -1, new RuntimeException());
+$previous = new TestingSuppressedExceptionsException('previous', -1, new \RuntimeException());
 $exception1 = new TestingSuppressedExceptionsException('message', 42, $previous);
-$exception1->addSuppressed(new RuntimeException('message', 0, $previous));
+$exception1->addSuppressed(new \RuntimeException('message', 0, $previous));
 
 $exception2 = new TestingSuppressedExceptionsException('message2', 42);
 $exception2->addSuppressed($previous);