Fix ISO code for Canadian French (#26015)

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

db/migrate/20240109103012_fix_canadian_french_locale.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class FixCanadianFrenchLocale < ActiveRecord::Migration[7.0]
+  class User < ApplicationRecord
+    # Dummy class, to make migration possible across version changes
+  end
+
+  disable_ddl_transaction!
+
+  def up
+    User.where(locale: 'fr-QC').in_batches do |users|
+      users.update_all(locale: 'fr-CA')
+    end
+  end
+
+  def down
+    User.where(locale: 'fr-CA').in_batches do |users|
+      users.update_all(locale: 'fr-QC')
+    end
+  end
+end