Update CI matrix

- Remove test for Gemfile against Ruby 3.1 because Rails main branch now requires Ruby 3.2.
- Add tests for Rails 8.0.0.rc1 or higher with Ruby 3.2 that is minimum required version for Rails 8.0.

Author: yahonda

.github/workflows/ci.yml

@@ -27,8 +27,11 @@ jobs:
           - ruby: 3.1
             gemfile: "gemfiles/Gemfile.rails-7.2-sprockets-4"
 
-          - ruby: 3.1
-            gemfile: Gemfile
+          - ruby: 3.2
+            gemfile: "gemfiles/Gemfile.rails-8.0-sprockets-3"
+          - ruby: 3.2
+            gemfile: "gemfiles/Gemfile.rails-8.0-sprockets-4"
+
           - ruby: 3.2
             gemfile: Gemfile
           - ruby: 3.3

gemfiles/Gemfile.rails-8.0-sprockets-3

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+gemspec path: '..'
+
+gem 'actionpack', '~> 8.0.0.rc1'
+gem 'railties', '~> 8.0.0.rc1'
+gem 'sprockets', '~> 3.0'

gemfiles/Gemfile.rails-8.0-sprockets-4

@@ -0,0 +1,6 @@
+source 'https://rubygems.org'
+gemspec path: '..'
+
+gem 'actionpack', '~> 8.0.0.rc1'
+gem 'railties', '~> 8.0.0.rc1'
+gem 'sprockets', '~> 4.0'