fix: Fix installation

[camdecoster]

Description

Update dependencies to fix npm install.

Closes #444.

Changes

• Update dependencies
• Update gulpfile per dependency changes
• Install specific version of bundler in makefile
• Remove unneeded yarn.lock

Testing

• Be on this branch
• Run make setup
  • If you use uv, you might need to prefix the pip install command: uv pip install
• Make sure install completed successfully
• Run the site locally and make sure it loads properly
• Also check that CI isn't failing

Notes

• While investigating this issue, I discovered that the main CSS files have been updated by hand and have diverged (a lot) from the SCSS files that previously compiled to those CSS files
• As such, don't compile the SCSS as it will blow away the hand written CSS
• I'm not going to fix it right now because there needs to be a much bigger overhaul of this docs repo