databases/ruby-sequel: update to 5.71.0

5.71.0 (2023-08-01)

* Support ILIKE ANY on PostgreSQL by not forcing the use of ESCAPE for ILIKE
  (gilesbowkett) (#2066)

* Add pg_xmin_optimistic_locking plugin for optimistic locking for all
  models without database changes (jeremyevans)

* Recognize the xid PostgreSQL type as an integer type in the
  jdbc/postgresql adapter (jeremyevans)

* Make set_column_allow_null method reversible in migrations (enescakir)
  (#2060)

(taca)