Correct phpbench.schema.json

[johnbillion]

These two config options are arrays, not objects.

I think several of the other config options defined as objects are also arrays, but I've not used or tested them to be sure.

[dantleech]

The schema is generated, so will need to fix the generator rather

[szepeviktor]

need to fix the generator

phpbench/lib/Development/ConfigSchemaDumper.php

Lines 84 to 89 in 6d269eb

	private function mapTypes(array $types): array
	{
	return array_map(function (string $type) {
	if ($type === 'array') {
	return 'object';
	}