web: kanban more menu is cropped on mobile

This commit removes some historical overflow-x properties needed
for old kanban views.

Steps to reproduce:
* Open Project App
* In kanban view and with one element, click on "more button" (3 dots)
* This menu will be truncated at the end. (BUG)

Task ID: 2058510

closes odoo/odoo#37693

Signed-off-by: Romeo Fragomeli <rfr@odoo.com>
Signed-off-by: Adrien Dieudonné (adr) <adr@odoo.com>

addons/web/static/src/scss/kanban_view.scss

@@ -7,7 +7,6 @@
 
     @include media-breakpoint-down(sm) {
         padding: 0px!important;
-        overflow-x: auto;
     }
 
     .o_kanban_record, .o_kanban_quick_create {

addons/web/static/src/scss/kanban_view_mobile.scss

@@ -30,7 +30,6 @@
         // [class] to get same specificity as elsewhere (kanban_view.less)
         &[class] .o_kanban_group:not(.o_column_folded) {
             @include o-position-absolute($top: $o-kanban-mobile-tabs-height, $left: 0, $bottom: 0);
-            overflow-x: scroll;
             width: 100%;
             padding: 0;
             margin-left: 0; // override the margin-left: -1px of the desktop mode