[Bug] Codespace/devcontainer fails to build

[rossboast]

Describe the bug
I get the following ruby error when starting a codespace from the main branch:

#7 [dev_container_auto_added_stage_label 3/7] RUN gem install bundler github-pages
2026-01-21 16:44:16.963Z: #7 16.90 ERROR:  Error installing bundler:
#7 16.90 	The last version of bundler (>= 0) to support your Ruby & RubyGems was 2.4.22. Try installing it with `gem install bundler -v 2.4.22`
#7 16.90 	bundler requires Ruby version >= 3.2.0. The current ruby version is 2.7.8.225.
2026-01-21 16:46:29.751Z: #7 149.7 ERROR:  Error installing github-pages:
#7 149.7 	There are no versions of nokogiri (>= 1.16.2, < 2.0) compatible with your Ruby & RubyGems. Maybe try installing an older version of the gem you're looking for?
#7 149.7 	nokogiri requires Ruby version >= 3.2, < 4.1.dev. The current ruby version is 2.7.8.225.
2026-01-21 16:46:29.995Z: #7 149.8 Successfully installed webrick-1.9.2
#7 149.8 Successfully installed unicode-display_width-1.8.0
#7 149.8 Successfully installed terminal-table-1.8.0
2026-01-21 16:46:30.051Z: #7 ERROR: process "/bin/sh -c gem install bundler github-pages" did not complete successfully: exit code: 1
2026-01-21 16:46:30.099Z: ------2026-01-21 16:46:30.101Z: 
 [dev_container_auto_added_stage_label 3/7] RUN gem install bundler github-pages:
16.90 ERROR:  Error installing bundler:
16.90 	The last version of bundler (>= 0) to support your Ruby & RubyGems was 2.4.22. Try installing it with `gem install bundler -v 2.4.22`
16.90 	bundler requires Ruby version >= 3.2.0. The current ruby version is 2.7.8.225.
149.7 ERROR:  Error installing github-pages:
149.7 	There are no versions of nokogiri (>= 1.16.2, < 2.0) compatible with your Ruby & RubyGems. Maybe try installing an older version of the gem you're looking for?
149.7 	nokogiri requires Ruby version >= 3.2, < 4.1.dev. The current ruby version is 2.7.8.225.

To Reproduce
Steps to reproduce the behavior:

1. Go to Code
2. Click on CodeSpaces
3. Click on + to create a new CodeSpace
4. See error in creation.log

Error is reproducible when running the devcontainer locally also.

Expected behavior
A working codespace.