List of steps to reproduce (step by step, including full links if applicable):

• Go to https://doc.wikimedia.org/oojs-ui/master/demos
• Click on "PHP" in the heading

What happens?:

It directs me to https://doc.wikimedia.org/oojs-ui/master/demos/demos.php?page=widgets&theme=wikimediaui&direction=ltr&platform=desktop
and I see Composer detected issues in your platform: Your Composer dependencies require a PHP version ">= 7.2.9".

What should have happened instead?:

The PHP demo page should have loaded.