Fatal errors with PHP 8 + HyperDB

Hello,

The Events Calendar triggers a fatal error when using HyperDB (https://github.com/Automattic/HyperDB) and PHP 8:

Fatal error: Uncaught Error: mysqli_result object is already closed in /var/www/wp-content/db.php on line 1437

Call stack:

    mysqli_num_fields()
    wp-content/db.php:1437

    hyperdb::ex_mysql_num_fields()
    wp-content/db.php:973

    hyperdb::query()
    wp-includes/wp-db.php:2722

    wpdb::get_var()
    wp-includes/class-wp-query.php:3381

    WP_Query::set_found_posts()
    wp-includes/class-wp-query.php:3065

    WP_Query::get_posts()
    wp-content/plugins/the-events-calendar/common/src/Tribe/Repository.php:656

    Tribe__Repository::found()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/View.php:2433

    Tribe\E\V\V\View::upcoming_events_count()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/View.php:1907

    Tribe\E\V\V\View::setup_messages()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/View.php:1491

    Tribe\E\V\V\View::setup_template_vars()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/Views/List_View.php:265

    Tribe\E\V\V\V\List_View::setup_template_vars()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/View.php:646

    Tribe\E\V\V\View::get_html()
    wp-content/plugins/the-events-calendar/src/Tribe/Views/V2/Template_Bootstrap.php:262

    Tribe\E\V\V\Template_Bootstrap::get_view_html()
    wp-content/plugins/the-events-calendar/src/views/v2/default-template.php:19

    include()
    wp-includes/template-loader.php:106

    require_once()
    wp-blog-header.php:19

    require()
    index.php:17

Here are the steps to reproduce the issue:

1. Install WordPress v6.0.1
2. Install HyperDB v1.8, using the default config (just copy db.php and db-config.php as-is right from the repo)
3. Ensure the site is on PHP 7 (if you try to install the plugin on PHP 8 with HyperDB, it fatals and doesn’t install)
4. Install and activate The Events Calendar v6.0.0.1
5. Switch the test site to PHP 8
6. Add and publish a test event: WP Admin → Events → Add New
7. Visit the Events archive page (WP Admin → Events (in admin bar) → View Calendar, or by appending ?post_type=tribe_events to your test site URL)
8. Observe the fatal error triggered

The issue appears to be with how the plugin is filtering posts_pre_query, as when I comment out the following line the fatals go away:

https://plugins.trac.www.ads-software.com/browser/the-events-calendar/tags/6.0.0.1/src/Events/Custom_Tables/V1/WP_Query/Modifiers/Events_Only_Modifier.php#L47