fix: report dataset provider errors as failing tests (#1749)

Errors raised while resolving a test's dataset (missing named dataset,
throwing dataset closure) previously crashed the whole run. Now the data
provider catches them, wraps them in a DatasetProviderError, and the test
method rethrows the original throwable so the affected test fails cleanly
with a non-zero exit code while other tests keep running.

src/Exceptions/DatasetProviderError.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Exceptions;
+
+use RuntimeException;
+use Throwable;
+
+/**
+ * @internal
+ */
+final class DatasetProviderError extends RuntimeException
+{
+    public function __construct(Throwable $previous)
+    {
+        parent::__construct($previous->getMessage(), (int) $previous->getCode(), $previous);
+    }
+}