Update workflows

Drops testing support for:

Ruby 2.6 + Ruby 2.7: These have been EOL'd and should no longer be used.
Rails 5.2: This version has been EOL'd as well.

.github/workflows/ruby.yml

@@ -17,39 +17,15 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby_version: [3.2, 3.1, "3.0", 2.7, 2.6, jruby]
+        ruby_version: [3.3, 3.2, 3.1, jruby]
         gemfile:
           - Gemfile
-          - gemfiles/Gemfile.rails-5.2.x
           - gemfiles/Gemfile.rails-6.0.x
           - gemfiles/Gemfile.rails-6.1.x
           - gemfiles/Gemfile.rails-7.0.x
+          - gemfiles/Gemfile.rails-7.1.x
           - gemfiles/Gemfile.rails-main
         exclude:
-          # Ruby 3.2 is not supported by Rails 5.2.x
-          - ruby_version: 3.2
-            gemfile: gemfiles/Gemfile.rails-5.2.x
-
-          # Ruby 3.1 is not supported by Rails 5.2.x
-          - ruby_version: 3.1
-            gemfile: gemfiles/Gemfile.rails-5.2.x
-
-          # Ruby 3.x is not supported by Rails 5.2.x
-          - ruby_version: "3.0"
-            gemfile: gemfiles/Gemfile.rails-5.2.x
-
-          # Ruby 2.6.x is not supported by Rails main
-          - ruby_version: 2.6
-            gemfile: gemfiles/Gemfile.rails-main
-
-          # Ruby 2.6.x is not supported by Rails 7.0.x
-          - ruby_version: 2.6
-            gemfile: gemfiles/Gemfile.rails-7.0.x
-
-          # JRuby 9.4.2.0 (3.1.0) is not supported by Rails 5.2.x
-          - ruby_version: jruby
-            gemfile: gemfiles/Gemfile.rails-5.2.x
-
           # JRuby is not supported by Rails 7.0.x
           - ruby_version: jruby
             gemfile: gemfiles/Gemfile.rails-7.0.x

gemfiles/Gemfile.rails-7.1.x

@@ -0,0 +1,13 @@
+source 'https://rubygems.org'
+
+gemspec :path => '..'
+
+gem 'activesupport', '~> 7.1'
+gem 'mocha', '~> 1.7.0'
+gem 'test_declarative', '0.0.6'
+gem 'rake'
+gem 'minitest', '~> 5.14'
+
+platforms :mri do
+  gem 'oj'
+end