`ActiveRecord::ReadonlyAttributeError` seems to be missing from `activerecord`

[stevegeek]

Hi all,

ActiveRecord::ReadonlyAttributeError seems to be missing from the RBS of activerecord (checked against 8.0 => https://github.com/ruby/gem_rbs_collection/blob/main/gems/activerecord/8.0/activerecord-generated.rbs)

In AR it is defined here:

https://github.com/rails/rails/blob/af024b591f8525e51402b897383fc8a0d9bb8ffc/activerecord/lib/active_record/readonly_attributes.rb#L4