Website builds locally, but not with GitHub Actions

My site builds locally, but when I try to deploy with GitHub Actions, I get the following error.
The full log is available here.

Failed to build the site
Error: Failed to render section '/github/workspace/content/_index.md'
Reason: Failed to render 'index.html': error while rendering macro `macros_header::header` (error happened in a parent template)
Reason: Variable `config.default_language` not found in context while rendering 'macros/header.html'

I set default_language in my config.toml.

# The URL the site will be built for
base_url = "jcarpinelli.dev"

# Open source theme
theme = "adidoks"

title = "Home"
description = "A personal website which serves as a portfolio, and a publishing platform for open-source software documentation, educational content and blog posts."

# Whether to automatically compile all Sass files in the sass directory
compile_sass = true
minify_html = true
generate_feed = true
feed_filename = "rss.xml"

# Whether to build a search index to be used later on by a JavaScript library
build_search_index = true

[markdown]
# Whether to do syntax highlighting
# Theme can be customised by setting the `highlight_theme` variable to a theme supported by Zola
highlight_code = true

# The default language; used in feeds and search index
# Note: the search index doesn't support Chinese/Japanese/Korean Languages
default_language = "en"

[search]
# Whether to include the title of the page/section in the index
include_title = true
# Whether to include the description of the page/section in the index
include_description = false
# Whether to include the rendered content of the page/section in the index
include_content = true

[extra]
# Put all your custom variables here
author = "Joey Carpinelli"
github = "https://github.com/cadojo"
twitter = "https://twitter.com/code_typed"
email = "joe.cadojo@icloud.com"

# If running on netlify.app site, set to true
is_netlify = false

# Set HTML file language
language_code = "en-US"

# Set theme-color meta tag for Chrome browser
theme_color = "#fff"

# More about site's title
title_separator = "|"  # set as |, -, _, etc
title_addition = "Joe(y) Carpinelli"


# Set date format in blog publish metadata
timeformat = "%Y-%m-%d" # e.g. 2021-05-01 09:19:42
timezone = "UTC"

# Edit page on reposity or not
edit_page = false
docs_repo = "https://github.com/cadojo/cadojo.github.io"
repo_branch = "main"

## Math settings
# options: true, false. Enable math support globally,
# default: false. You can always enable math on a per page.
math = false
library = "katex"  # options: "katex", "mathjax". default is "katex".

## Open Graph + Twitter Cards
[extra.open]
enable = true
# this image will be used as fallback if a page has no image of its own
image = "doks.png"
twitter_site = "code_typed"
twitter_creator = "code_typed"
facebook_author = ""
facebook_publisher = ""
og_locale = "en_US"

## JSON-LD
[extra.schema]
type = "Organization"
logo = "logo-doks.png"
twitter = "https://twitter.com/code_typed"
linked_in = ""
github = "https://github.com/code_typed"
section = "blog" # see config.extra.main~url
## Sitelinks Search Box
site_links_search_box = false


[[extra.menu.social]]
name = "Twitter"
pre = '<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-twitter"><path d="M23 3a10.9 10.9 0 0 1-3.14 1.53 4.48 4.48 0 0 0-7.86 3v1A10.66 10.66 0 0 1 3 4s-4 9 5 13a11.64 11.64 0 0 1-7 2c9 5 20 0 20-11.5a4.5 4.5 0 0 0-.08-.83A7.72 7.72 0 0 0 23 3z"></path></svg>'
url = "https://twitter.com/code_typed"
weight = 10

[[extra.menu.social]]
name = "GitHub"
pre = '<svg xmlns="http://www.w3.org/2000/svg" width="20" height="20" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-github"><path d="M9 19c-5 1.5-5-2.5-7-3m14 6v-3.87a3.37 3.37 0 0 0-.94-2.61c3.14-.35 6.44-1.54 6.44-7A5.44 5.44 0 0 0 20 4.77 5.07 5.07 0 0 0 19.91 1S18.73.65 16 2.48a13.38 13.38 0 0 0-7 0C6.27.65 5.09 1 5.09 1A5.07 5.07 0 0 0 5 4.77a5.44 5.44 0 0 0-1.5 3.78c0 5.42 3.3 6.61 6.44 7A3.37 3.37 0 0 0 9 18.13V22"></path></svg>'
url = "https://github.com/cadojo"
post = "v0.1.0"
weight = 20

# Footer contents
[extra.footer]
info = '© Joey Carpinelli. Website generated with <a href="https://www.getzola.org/">Zola</a>, and <a href="https://github.com/aaranxu/adidoks">AdiDoks!</a>'

I suspect the issue has something to do with GitHub’s expected root directory not matching Zola’s, but I’m not sure how to correct this. I include a CNAME file at the root of static, as instructed in the documentation.

The site source code is available at GitHub - cadojo/cadojo.github.io: Personal sites, repository documentation, and (one day, maybe) more!. Does anyone see anything glaring?

You put it in the markdown section, you have it put it out of any sections, like below build_search_index = true.