This commit introduces an optimization to reduce the number of read operations performed in kanban views that are grouped by a field with a group_by_tooltip. Specifically, we now fetch the required values from group_by_tooltip only when the tooltip is first opened, instead of performing a read every time the view is loaded. Part of Task: 3179751 closes odoo/odoo#117758 Related: odoo/enterprise#39349 Signed-off-by: Aaron Bohy (aab) <aab@odoo.com>