CI fixes

Author: Igor

imageboss-rails.gemspec

@@ -34,8 +34,8 @@ Gem::Specification.new do |s|
 
   s.add_dependency 'rails', rails
 
-  # Rails 5.2, 6.1, and 8.0 LineFiltering#run expects 2 args; Minitest 6 passes 3. Pin to 5.x.
-  if rails_version != "default" && (rails_version.start_with?("5.") || rails_version.start_with?("6.1") || rails_version.start_with?("8.0"))
+  # From Rails 5 onward, LineFiltering#run expects 2 args; Minitest 6 passes 3. Pin to 5.x when testing a specific Rails version.
+  if rails_version != "default"
     s.add_development_dependency "minitest", "~> 5.14"
   end