Delete calculator currency values from db [migration]

This depends on openfoodfoundation#10318 being deployed first.

db/migrate/20230126233821_delete_calculator_currency_from_spree_preferences.rb

@@ -0,0 +1,15 @@
+class DeleteCalculatorCurrencyFromSpreePreferences < ActiveRecord::Migration[6.1]
+  class SpreePreference < ActiveRecord::Base
+  end
+
+  def up
+    # Delete all currency preferences for calculators, they are no longer used.
+    rows = SpreePreference.where("key like '/calculator%/currency/%'").delete_all
+    puts "#{rows} rows deleted."
+  end
+
+  def down
+    # Sorry, the data was deleted!
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2023_01_17_043628) do
+ActiveRecord::Schema.define(version: 2023_01_26_233821) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"