chore: upgrade ruby version to 3.4.4 (#11524)

- Chore upgrade ruby version to 3.4.4 before we migrate to rails 7.2
over #11037

app/models/conversation.rb

@@ -128,6 +128,12 @@ class Conversation < ApplicationRecord
     additional_attributes&.dig('conversation_language')
   end
 
+  # Be aware: The precision of created_at and last_activity_at may differ from Ruby's Time precision.
+  # Our DB column (see schema) stores timestamps with second-level precision (no microseconds), so
+  # if you assign a Ruby Time with microseconds, the DB will truncate it. This may cause subtle differences
+  # if you compare or copy these values in Ruby, also in our specs
+  # So in specs rely on to be_with(1.second) instead of to eq()
+  # TODO: Migrate to use a timestamp with microsecond precision
   def last_activity_at
     self[:last_activity_at] || created_at
   end