Bundler attempts to install gems specified with `platforms: :mri` on TruffleRuby (and maybe jruby too)

Describe the problem as clearly as you can

Gemfile has:

gem 'fiber_scheduler', platforms: :mri

On TruffleRuby (RUBY_VERSION 3.0.3), bundler 2.4.6 attempts to install fiber_scheduler gem. Ultimately this fails, as fiber_scheduler requires RUBY_VERSION >= 3.1.0

However, bundler should not even attempt to install a gem specified with platforms: :mri on TruffleRuby. Per https://bundler.io/v2.4/man/gemfile.5.html#PLATFORMS

See here: https://github.com/rickhull/miner_mover/actions/runs/4067260405/jobs/7004396321#step:6:9

Run bundle install
  bundle install
  shell: /usr/bin/bash -e {0}
Fetching gem metadata from https://rubygems.org/.......
Resolving dependencies...
Could not find compatible versions

Because every version of fiber_scheduler depends on Ruby >= 3.1.0
  and Gemfile depends on fiber_scheduler >= 0,
  Ruby >= 3.1.0 is required.
So, because current Ruby version is = 3.0.3,
  version solving has failed.
Error: Process completed with exit code 6.

Did you try upgrading rubygems & bundler?

Yes. See here: https://github.com/rickhull/miner_mover/actions/runs/4067260405/jobs/7004396321#step:5:10

Post steps to reproduce the problem

Create Gemfile:

source 'https://rubygems.org/'
gem 'fiber_scheduler', platforms: :mri

On TruffleRuby 3.0.3, after updating RubyGems and Bundler, run: bundle install

Which command did you run?

bundle install

What were you expecting to happen?

gem install fiber_scheduler should not be attempted

What actually happened?

bundler attempted to install fiber_scheduler gem on TruffleRuby

Reproduce the issue with the shown Gemfile on TruffleRuby 3.0.3 by running bundle install after updating RubyGems and Bundler. Trace Bundler's handling of the platforms: :mri declaration and verify that fiber_scheduler is not attempted on TruffleRuby, while the command continues to resolve correctly.