Prep 9.0.6 (#5956)

* version bump

* Rails 6.1 requires older concurrent-ruby gem

See https://stackoverflow.com/questions/79360526

Author: jamis

gemfiles/rails-6.1.gemfile

@@ -1,6 +1,9 @@
 # rubocop:todo all
 source 'https://rubygems.org'
 
+# See https://stackoverflow.com/questions/79360526
+gem 'concurrent-ruby', '< 1.3.5'
+
 gem 'actionpack', '~> 6.1'
 gem 'activemodel', '~> 6.1'
 

lib/mongoid/version.rb

@@ -2,5 +2,5 @@
 # rubocop:todo all
 
 module Mongoid
-  VERSION = "9.0.5"
+  VERSION = "9.0.6"
 end

spec/integration/app_spec.rb

@@ -26,6 +26,10 @@ def insert_rails_gem_version(cmd)
       skip 'Set APP_TESTS=1 in environment to run application tests'
     end
 
+    if SpecConfig.instance.rails_version < '7.1'
+      skip 'App tests require Rails > 7.0 (see https://stackoverflow.com/questions/79360526)'
+    end
+
     require 'fileutils'
     require 'mrss/child_process_helper'
     require 'open-uri'