Limit beaker-puppet to older Rubies

[mhashizume]

No version of beaker-puppet is compatible with Ruby >= 3.2 because of taint functions. Because beaker-puppet specifies that it cannot run on Ruby < 3.1 in its gemspec, when you run bundle install on newer Rubies- even when excluding the Gem group to which beaker-puppet belongs- Bundler errors.

This commit updates the Gemfile to only list beaker-puppet if Ruby is less than 3.1.0.

[mhashizume]

This issue surfaced because the release prep action for this module, which is running on Ruby 3.2, failed: https://github.com/puppetlabs/puppetlabs-augeas_core/actions/runs/8052884890

We can see this behavior in main:

$ ruby -v
ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [arm64-darwin23]
$ git describe
1.1.2-77-g433594e
$ export BUNDLE_ONLY=release_prep
$ bundle install
. . .
Could not find compatible versions

Because beaker-puppet >= 3.0.0 depends on Ruby >= 2.7, < 3.2
  and Gemfile depends on beaker-puppet ~> 3.0,
  Ruby >= 2.7, < 3.2 is required.
So, because current Ruby version is = 3.2.3,
  version solving has failed.

And it behaving as expected with this PR:

$ ruby -v
ruby 3.2.3 (2024-01-18 revision 52bb2ac0a6) [arm64-darwin23]
$ git describe
1.1.2-78-gd9b280e
$ export BUNDLE_ONLY=release_prep
$ bundle install
. . . 
Bundle complete! 31 Gemfile dependencies, 31 gems now installed.
Gems in the groups 'development' and 'system_tests' were not installed.
Use `bundle info [gemname]` to see where a bundled gem is installed.