Currently, all of the tasks contained in a stage are archived when the stage is archived. However, the tasks remained archived when the stage is unarchived. So in this commit, If the user unarchives a stage, ask the user to unarchive the tasks it contains in the process. task-2835624 closes odoo/odoo#94008 Related: odoo/enterprise#28301 Signed-off-by: Laurent Stukkens (ltu) <ltu@odoo.com>