Sinatra tests fail or timeout with Bundler 4

[dentarg]

See https://github.com/sinatra/sinatra/actions/runs/20510062061/job/58929968816#step:5:36

The source contains the following gems matching 'sass-embedded (~> 1.54)':
  * sass-embedded-1.97.1-x86_64-linux-gnu
	from /home/runner/.rubies/ruby-head/lib/ruby/4.0.0+0/bundler/resolver.rb:450:in 'block in Bundler::Resolver#prepare_dependencies'
...

Logs attached:

17_ruby-head(Rack stable, RackSession stable, Puma stable, Tilt stable, Zeitwerk stable).txt

[dentarg]

Is it this? ruby/rubygems#9213 (I haven't verified)