= New Features

* Objects that respond to sql_literal_append or sql_literal to
  support custom literalization in Sequel datasets can now also
  implement the sql_literal_allow_caching? method.  If the object
  responds to the method and it returns true, then Sequel will
  still allow caching of the Dataset's SQL (this is disabled by
  default as Sequel cannot be sure that the literalization will
  not change between calls).

* Model.qualified_primary_key has been added, which returns an
  SQL::QualifiedIdentifier with the model's primary key, or an
  array of SQL::QualifiedIdentifier objects if the model uses a
  composite primary key.

* set_column_not_null is now a reversible method in migrations.

= Other Improvements

* The Model dataset paged_each method and the dataset methods in
  the paged_operations plugin now automatically use a qualified
  primary key instead of an unqualified primary key if the dataset
  is joined.

* Module temporary names when using Ruby 3.5 are now consistent
  with Ruby 3.3 and 3.4.
