PHP 8.1 Deprecation notice at yoast-seo.php: "Automatic conversion of false to array is deprecated"

[alfonso100]

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Describe the bug

When using PHP 8.1, we'll get a Deprecation notice:

Automatic conversion of false to array is deprecated wp-content/plugins/wp-rocket/inc/3rd-party/plugins/seo/yoast-seo.php:10

it is happening here:

wp-rocket/inc/3rd-party/plugins/seo/yoast-seo.php

Line 10 in 9d3313b

$yoast_seo_xml['enablexmlsitemap'] = isset( $yoast_seo['enable_xml_sitemap'] ) && $yoast_seo['enable_xml_sitemap']; // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals

To Reproduce
Steps to reproduce the behavior:

1. Update to PHP 8.1
2. Enable Yoast SEO and activate sitemap preload
3. See the deprecation notice

Expected behavior
We should not cause any deprecation notices

Screenshots
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Additional context
Ticket: https://secure.helpscout.net/conversation/1816071909/331622?folderId=2683093

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