Use Ruby 3.3 to fix generation

[zzak]

Similar to #29, have manually verified this on the server:

$ FORCE=1 bin/rails_master_hook.sh

[2025-01-06 07:07:51 UTC]  rvm 3.3.6 do gem install bundler >/dev/null
[2025-01-06 07:08:01 UTC]  rvm 3.3.6 do bundle install --without db test job cable storage ujs >/dev/null
[DEPRECATED] The `--without` flag is deprecated because it relies on being remembered across bundler invocations, which bundler will no longer do
in future versions. Instead please use `bundle config set without 'db test job cable storage ujs'`, and stop using this flag
[2025-01-06 07:08:04 UTC] EDGE="1" ALL="1" rvm 3.3.6 do bundle exec rake rdoc >/dev/null

Generating API format into /home/rails/main/doc/rdoc...
[2025-01-06 07:10:37 UTC] ALL="1" rvm 3.3.6 do bundle exec rake guides:generate:html >/dev/null
/home/rails/.rvm/rubies/ruby-3.3.6/bin/ruby -Eutf-8:utf-8 rails_guides.rb
...
[2025-01-06 07:11:02 UTC] gzip -c -9 /home/rails/main/guides/output/working_with_javascript_in_rails.html > /home/rails/main/guides/output/working
_with_javascript_in_rails.html.gz
[2025-01-06 07:11:02 UTC] Done
[2025-01-06 07:11:02 UTC] releasing lock file docs_generation.lock

Sorry, I don't have time to investigate a proper fix at the moment.

/cc @skipkayhil