Update to Rails 7.2 and 8 in tests

* Rails <= 6 has a known issue with logger and the workaround causes CI failures:
  https://github.com/ruby/setup-ruby/actions/runs/14641011806/job/41083255632

Author: eregon

.github/workflows/test.yml

@@ -369,7 +369,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        gemfile: [ rails5, rails6 ]
+        gemfile: [ rails7, rails8 ]
     name: "Test with ${{ matrix.gemfile }} gemfile"
     runs-on: ubuntu-latest
     env:
@@ -378,11 +378,9 @@ jobs:
       - uses: actions/checkout@v4
       - uses: ./
         with:
-          ruby-version: '2.6'
+          ruby-version: '3.2'
           bundler-cache: true
       - run: bundle exec rails --version
-        env:
-          RUBYOPT: '-rlogger' # Rails 6 is missing a require 'logger' in active_support/logger_thread_safe_level.rb
 
   testTruffleRubyNokogiri:
     name: "Test installing a Gemfile with nokogiri on TruffleRuby"

gemfiles/rails5.gemfile renamed to gemfiles/rails7.gemfile

@@ -1,3 +1,3 @@
 source "https://rubygems.org"
 
-gem "rails", "~> 5.2.0"
+gem "rails", "~> 7.2.0"

gemfiles/rails6.gemfile renamed to gemfiles/rails8.gemfile

@@ -1,3 +1,3 @@
 source "https://rubygems.org"
 
-gem "rails", "~> 6.0.0"
+gem "rails", "~> 8.0.0"