Add Ruby 3.3 to the CI matrix (#50)

Adding 3.4 is a bit more complicated, because no versions of Nokogiri
support 3.0 and 3.4. We'd need separate gemfiles, ro we'd need to only
test Ruby 3.4 against specific gemfiles.

.github/workflows/ci.yml

@@ -8,7 +8,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: ['2.7', '3.0', '3.1', '3.2']
+        ruby: ['2.7', '3.0', '3.1', '3.2', '3.3']
         gemfile:
           - gemfiles/rails_5_2.gemfile
           - gemfiles/rails_6_0.gemfile
@@ -18,6 +18,8 @@ jobs:
           - gemfiles/rails_7_2.gemfile
           - gemfiles/rails_8_0.gemfile
         exclude:
+          - ruby: '3.3'
+            gemfile: gemfiles/rails_5_2.gemfile
           - ruby: '3.2'
             gemfile: gemfiles/rails_5_2.gemfile
           - ruby: '3.1'

Appraisals

@@ -10,20 +10,23 @@ appraise 'rails-6-0' do
   gem 'activejob', '~> 6.0.0'
   gem 'activerecord', '~> 6.0.0'
   gem 'sqlite3', '~> 1.4'
+  gem 'concurrent-ruby', '1.3.4'
 end
 
 appraise 'rails-6-1' do
   gem 'actionmailer', '~> 6.1.0'
   gem 'activejob', '~> 6.1.0'
   gem 'activerecord', '~> 6.1.0'
   gem 'sqlite3', '~> 1.4'
+  gem 'concurrent-ruby', '1.3.4'
 end
 
 appraise 'rails-7-0' do
   gem 'actionmailer', '~> 7.0.0'
   gem 'activejob', '~> 7.0.0'
   gem 'activerecord', '~> 7.0.0'
   gem 'sqlite3', '~> 1.4'
+  gem 'concurrent-ruby', '1.3.4'
 end
 
 appraise 'rails-7-1' do

gemfiles/rails_6_0.gemfile

@@ -14,5 +14,6 @@ gem "rspec"
 gem "timecop"
 gem "zeitwerk"
 gem "sqlite3", "~> 1.4"
+gem "concurrent-ruby", "1.3.4"
 
 gemspec path: "../"

gemfiles/rails_6_1.gemfile

@@ -14,5 +14,6 @@ gem "rspec"
 gem "timecop"
 gem "zeitwerk"
 gem "sqlite3", "~> 1.4"
+gem "concurrent-ruby", "1.3.4"
 
 gemspec path: "../"

gemfiles/rails_7_0.gemfile

@@ -14,5 +14,6 @@ gem "rspec"
 gem "timecop"
 gem "zeitwerk"
 gem "sqlite3", "~> 1.4"
+gem "concurrent-ruby", "1.3.4"
 
 gemspec path: "../"