6.1 and 7.0 are affected only

integration/apps/rails-five/Gemfile

@@ -89,13 +89,3 @@ group :test, :development do
 
   gem 'listen'
 end
-
-# concurrent-ruby 1.3.5 removed dependency on logger, see:
-# https://github.com/ruby-concurrency/concurrent-ruby/commit/d7ce956dacd0b772273d39b8ed31a30cff7ecf38
-# Unfortunately this broke Rails because ActiveSupport used Logger
-# before requiring logger.
-# Since the failure happens rather early in rails bootstrapping,
-# patching it is difficult, thus downgrade concurrent-ruby.
-# The issue appears to affect all existing Rails versions:
-# https://github.com/rails/rails/blob/main/activesupport/lib/active_support/logger.rb#L4-L5
-gem 'concurrent-ruby', '1.3.4'

integration/apps/rails-seven/Gemfile

@@ -56,6 +56,7 @@ gem 'mutex_m'
 # before requiring logger.
 # Since the failure happens rather early in rails bootstrapping,
 # patching it is difficult, thus downgrade concurrent-ruby.
-# The issue appears to affect all existing Rails versions:
-# https://github.com/rails/rails/blob/main/activesupport/lib/active_support/logger.rb#L4-L5
+# The issue is fixed in 7-1-stable and should be shipped in the release
+# after 7.1.5.1.
+# See https://github.com/rails/rails/issues/54263
 gem 'concurrent-ruby', '1.3.4'

integration/apps/rails-six/Gemfile

@@ -112,6 +112,6 @@ gem 'mutex_m'
 # before requiring logger.
 # Since the failure happens rather early in rails bootstrapping,
 # patching it is difficult, thus downgrade concurrent-ruby.
-# The issue appears to affect all existing Rails versions:
-# https://github.com/rails/rails/blob/main/activesupport/lib/active_support/logger.rb#L4-L5
+# The issue affects Rails 6.1 where apparently it will be never fixed
+# (unlike Rails 7.0 which is fixed in https://github.com/rails/rails/issues/54263).
 gem 'concurrent-ruby', '1.3.4'