[FIX] web: fix kanban "group by stage" wrong display

Reproduce the issue

    - Install Projects and Studio
    - Edit the projects app's kanban view
    - Enable group by stage
    - Close studio
    - Add several stages

    The stages are wrapped to the next line

Cause

    I think the problem comes from c5f6802, we apply a wrapping to
    all the kanban_dashboard items and in this cases the items are
    the stages.

This commits apply the wrap only on non-grouped kanban dashboard.

OPW-2123031

closes odoo/odoo#40449

X-original-commit: f40478d5bacfdc44c76b0aac2f749549bbc58681
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>

addons/web/static/src/scss/kanban_dashboard.scss

@@ -1,7 +1,9 @@
 
 .o_kanban_view.o_kanban_dashboard {
-    // correctly display the no_content_helper in dashboards
-    flex-flow: row wrap;
+    &:not(.o_kanban_grouped) {
+        // correctly display the no_content_helper in dashboards
+        flex-flow: row wrap;
+    }
 
     .o_kanban_record {
         position: relative;