refacto(phpstan-to-8): few adjustments

src/Exceptions/InvalidExpectationValue.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Pest\Exceptions;
+
+use InvalidArgumentException;
+
+/**
+ * @internal
+ */
+final class InvalidExpectationValue extends InvalidArgumentException
+{
+    /**
+     * @return never
+     *
+     * @throws self
+     */
+    public static function expected(string $type): void
+    {
+        throw new self(sprintf('Invalid expectation value type. Expected [%s].', $type));
+    }
+}