Broken upstream dependency on Ruby sass

[handshape]

Describe the bug
The published Gemfile has an upstream dependency on a version of ruby-sass that has been deprecated and removed from rubygems.org (3.7.4)

To Reproduce
Steps to reproduce the behavior:

1. Install ruby on a fresh machine.
2. run gem install jekyll bundler
3. do a fresh clone of the gcweb-jekyll
4. run bundle
5. observe error message

Expected behavior
bundler will build the site

Error Message

Bundler::GemNotFound: Could not find sass-3.7.4.gem for installation
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/source/rubygems.rb:177:in `install'       
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/installer/gem_installer.rb:54:in `install'
/var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/installer/gem_installer.rb:16:in
`install_from_spec'
/var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/installer/parallel_installer.rb:186:in
`do_install'
/var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/installer/parallel_installer.rb:177:in
`block in worker_pool'
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/worker.rb:62:in `apply_func'
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/worker.rb:57:in `block in process_queue'
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/worker.rb:54:in `loop'
  /var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/worker.rb:54:in `process_queue'
/var/lib/gems/2.7.0/gems/bundler-2.2.30/lib/bundler/worker.rb:91:in `block (2 levels) in
create_threads'

An error occurred while installing sass (3.7.4), and Bundler cannot continue.

In Gemfile:
  github-pages was resolved to 221, which depends on
    jekyll-avatar was resolved to 0.7.0, which depends on
      jekyll was resolved to 3.9.0, which depends on
        jekyll-sass-converter was resolved to 1.5.2, which depends on
          sass

Desktop (please complete the following information):

• OS: Ubuntu
• Browser [e.g. chrome, safari]
• Version 21.10

[nschonni]

It hasn't been removed https://rubygems.org/gems/sass/versions/3.7.4

[handshape]

Hrm. You're right. If I hand-download the gem, it comes down. Any thoughts as to why invoking bundler emits the given error?

[nschonni]

No, note sure if there is a simple "cache clear" type command. I would usually just delete the vendor folder and try again

[handshape]

gem clean is the one for Ruby. I've removed all gems, done a new pull from the repo, retrieved a fresh jekyll and bundler, and the error yielded is the same. For the moment, I'll proceed with a simple Jekyll template (tested and working), matching the frontmatter scheme in this repo as closely as I can until the issue here can be resolved.