Ensure Minitest is loaded before RSpec OpenAPI

The alternative to this approach would be to remove the check for `Object.const_defined?('Minitest')`, but I assume in environments where you only have RSpec, not Minitest (like when you use another framework than Rails), this would not work.

spec/integration_tests/rails_test.rb

@@ -4,9 +4,8 @@
 ENV['RAILS_ENV'] ||= 'test'
 ENV['OPENAPI_OUTPUT'] ||= 'yaml'
 
-require File.expand_path('../rails/config/environment', __dir__)
-
 require 'minitest/autorun'
+require File.expand_path('../rails/config/environment', __dir__)
 
 RSpec::OpenAPI.request_headers = %w[X-Authorization-Token]
 RSpec::OpenAPI.response_headers = %w[X-Cursor]

spec/integration_tests/roda_test.rb

@@ -3,8 +3,8 @@
 require_relative '../roda/roda_app'
 require 'json'
 require 'rack/test'
-require 'rspec/openapi'
 require 'minitest/autorun'
+require 'rspec/openapi'
 
 ENV['OPENAPI_OUTPUT'] ||= 'yaml'