Issue:
The following error (see screenshot below) is being encountered when accessing the following pages:
home_page.html
content_page.html
blog_page.html

Steps To Reproduce The Error:
Start the wagtail.org server
To access the:

1. home_page.html head to pattern-library/pattern/patterns/pages/home/home_page.html
2. content_page.html head to pattern-library/pattern/patterns/pages/content_page/content_page.html
3. blog_page.html head to pattern-library/pattern/patterns/pages/blog/blog_page.html

Environment Used:
The issue occurs in both of these environments both using Docker and Chrome Browser Version 118.0.5993.117 (Official Build) (64-bit):

1. Gitpod
2. Locally (Ubuntu 22.0.4)