Tests not working against ruby 3.4 without bake-modernize

From my understanding `bake-modernize` is not required to run the tests and I would like to avoid that dependency.

```
==> Starting check()...
Cloning into '/build/ruby-bake-test-external/src/bake-test-external/external/sus'...
Fetching gem metadata from https://rubygems.org/.......
Fetching json 2.9.1
Installing json 2.9.1 with native extensions
Fetching racc 1.8.1
Installing racc 1.8.1 with native extensions
Bundle complete! 5 Gemfile dependencies, 19 gems now installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.
5 installed gems you directly depend on are looking for funding.
Run `bundle fund` for details
Cloning external repository sus...
Running external tests sus...
bundler: failed to load command: bake (/usr/bin/bake)
/usr/lib/ruby/3.4.0/bundler/resolver.rb:354:in 'Bundler::Resolver#raise_not_found!': Could not find gem 'bake-modernize' in l
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:445:in 'block in Bundler::Resolver#prepare_dependencies'
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:420:in 'Hash#each'
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:420:in 'Enumerable#filter_map'
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:420:in 'Bundler::Resolver#prepare_dependencies'
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:64:in 'Bundler::Resolver#setup_solver'
from /usr/lib/ruby/3.4.0/bundler/resolver.rb:29:in 'Bundler::Resolver#start'
from /usr/lib/ruby/3.4.0/bundler/definition.rb:723:in 'Bundler::Definition#start_resolution'
from /usr/lib/ruby/3.4.0/bundler/definition.rb:341:in 'Bundler::Definition#resolve'
from /usr/lib/ruby/3.4.0/bundler/definition.rb:632:in 'Bundler::Definition#materialize'
from /usr/lib/ruby/3.4.0/bundler/definition.rb:232:in 'Bundler::Definition#specs'
from /usr/lib/ruby/3.4.0/bundler/definition.rb:299:in 'Bundler::Definition#specs_for'
from /usr/lib/ruby/3.4.0/bundler/runtime.rb:18:in 'Bundler::Runtime#setup'
from /usr/lib/ruby/3.4.0/bundler.rb:167:in 'Bundler.setup'
from /usr/lib/ruby/3.4.0/bundler/setup.rb:32:in 'block in '
from /usr/lib/ruby/3.4.0/bundler/ui/shell.rb:173:in 'Bundler::UI::Shell#with_level'
from /usr/lib/ruby/3.4.0/bundler/ui/shell.rb:119:in 'Bundler::UI::Shell#silence'
from /usr/lib/ruby/3.4.0/bundler/setup.rb:32:in ''
from /usr/lib/ruby/3.4.0/bundler/cli/exec.rb:57:in 'Kernel#require_relative'
from /usr/lib/ruby/3.4.0/bundler/cli/exec.rb:57:in 'Bundler::CLI::Exec#kernel_load'
from /usr/lib/ruby/3.4.0/bundler/cli/exec.rb:23:in 'Bundler::CLI::Exec#run'
from /usr/lib/ruby/3.4.0/bundler/cli.rb:452:in 'Bundler::CLI#exec'
from /usr/lib/ruby/3.4.0/bundler/vendor/thor/lib/thor/command.rb:28:in 'Bundler::Thor::Command#run'
from /usr/lib/ruby/3.4.0/bundler/vendor/thor/lib/thor/invocation.rb:127:in 'Bundler::Thor::Invocation#invoke_command'
from /usr/lib/ruby/3.4.0/bundler/vendor/thor/lib/thor.rb:538:in 'Bundler::Thor.dispatch'
from /usr/lib/ruby/3.4.0/bundler/cli.rb:35:in 'Bundler::CLI.dispatch'
from /usr/lib/ruby/3.4.0/bundler/vendor/thor/lib/thor/base.rb:584:in 'Bundler::Thor::Base::ClassMethods#start'
from /usr/lib/ruby/3.4.0/bundler/cli.rb:29:in 'Bundler::CLI.start'
from /usr/lib/ruby/gems/3.4.0/gems/bundler-2.6.0/exe/bundle:28:in 'block in '
from /usr/lib/ruby/3.4.0/bundler/friendly_errors.rb:117:in 'Bundler.with_friendly_errors'
from /usr/lib/ruby/gems/3.4.0/gems/bundler-2.6.0/exe/bundle:20:in ''
from /usr/bin/bundle:25:in 'Kernel#load'
from /usr/bin/bundle:25:in ''
External tests sus failed!
2 passed 1 errored out of 3 total (3 assertions)
🏁 Finished in 5.3s; 0.564 assertions per second.
🐢 Slow tests:
5.2s: file test/bake/test/external.rb it should clone external repository test/bake/test/external.rb:11

🔥 Errored assertions:
file test/bake/test/external.rb it should run external tests test/bake/test/external.rb:17
⚠ RuntimeError: Command failed with exit 1: bundle
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:20 Kernel#system
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:20 Bake::Test::External::Controller#system!
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:102 block in Bake::Test::External::Controller#test_repository
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:101 Array#each
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:101 Bake::Test::External::Controller#test_repository
/build/ruby-bake-test-external/src/bake-test-external/lib/bake/test/external/controller.rb:41 Bake::Test::External::Controller#clone_and_test
/build/ruby-bake-test-external/src/bake-test-external/bake/test/external.rb:34 block (2 levels) in external
/usr/lib/ruby/3.4.0/bundler.rb:411 block in Bundler.with_unbundled_env
/usr/lib/ruby/3.4.0/bundler.rb:716 Bundler.with_env
/usr/lib/ruby/3.4.0/bundler.rb:411 Bundler.with_unbundled_env
/build/ruby-bake-test-external/src/bake-test-external/bake/test/external.rb:33 block in external
/build/ruby-bake-test-external/src/bake-test-external/bake/test/external.rb:29 Hash#each
/build/ruby-bake-test-external/src/bake-test-external/bake/test/external.rb:29 external
/usr/lib/ruby/gems/3.4.0/gems/bake-0.23.1/lib/bake/recipe.rb:114 Bake::Recipe#call
/usr/lib/ruby/gems/3.4.0/gems/bake-0.23.1/lib/bake/context.rb:99 Bake::Context#call
test/bake/test/external.rb:18 block (2 levels) in
```

Start with test/bake/test/external.rb, especially the external-test case reported at line 17, then trace the failing command through lib/bake/test/external/controller.rb:20 and :101-102. Reproduce the Ruby 3.4 failure and determine why the external sus tests require bake-modernize. Done means the external test runs successfully without that dependency.

Written by the indexing model from the issue text.