Add Ruby 3.0 support (#16046)

* Fix issues with POSIX::Spawn, Terrapin and Ruby 3.0

Also improve the Terrapin monkey-patch for the stderr/stdout issue.

* Fix keyword argument handling throughout the codebase

* Monkey-patch Paperclip to fix keyword arguments handling in validators

* Change validation_extensions to please CodeClimate

* Bump microformats from 4.2.1 to 4.3.1

* Allow Ruby 3.0

* Add Ruby 3.0 test target to CircleCI

* Add test for admin dashboard warnings

* Fix admin dashboard warnings on Ruby 3.0

2 files changed, 13 insertions, 8 deletions

diff --git a/app/models/session_activation.rb b/app/models/session_activation.rb
index b0ce9d112..3a59bad93 100644
--- a/app/models/session_activation.rb
+++ b/app/models/session_activation.rb
@@ -44,7 +44,7 @@ class SessionActivation < ApplicationRecord
     end
 
     def activate(**options)
-      activation = create!(options)
+      activation = create!(**options)
       purge_old
       activation
     end
diff --git a/app/models/user.rb b/app/models/user.rb
index 0440627c5..4973c68b6 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -370,15 +370,20 @@ class User < ApplicationRecord
 
   protected
 
-  def send_devise_notification(notification, *args)
+  def send_devise_notification(notification, *args, **kwargs)
     # This method can be called in `after_update` and `after_commit` hooks,
     # but we must make sure the mailer is actually called *after* commit,
     # otherwise it may work on stale data. To do this, figure out if we are
     # within a transaction.
+
+    # It seems like devise sends keyword arguments as a hash in the last
+    # positional argument
+    kwargs = args.pop if args.last.is_a?(Hash) && kwargs.empty?
+
     if ActiveRecord::Base.connection.current_transaction.try(:records)&.include?(self)
-      pending_devise_notifications << [notification, args]
+      pending_devise_notifications << [notification, args, kwargs]
     else
-      render_and_send_devise_message(notification, *args)
+      render_and_send_devise_message(notification, *args, **kwargs)
     end
   end
 
@@ -389,8 +394,8 @@ class User < ApplicationRecord
   end
 
   def send_pending_devise_notifications
-    pending_devise_notifications.each do |notification, args|
-      render_and_send_devise_message(notification, *args)
+    pending_devise_notifications.each do |notification, args, kwargs|
+      render_and_send_devise_message(notification, *args, **kwargs)
     end
 
     # Empty the pending notifications array because the
@@ -403,8 +408,8 @@ class User < ApplicationRecord
     @pending_devise_notifications ||= []
   end
 
-  def render_and_send_devise_message(notification, *args)
-    devise_mailer.send(notification, self, *args).deliver_later
+  def render_and_send_devise_message(notification, *args, **kwargs)
+    devise_mailer.send(notification, self, *args, **kwargs).deliver_later
   end
 
   def set_approved