[FIX] web: properly clear floats in kanban records

Before the new design, floats in kanban records were cleared using the
clearfix method. Now, the kanban color requires using the ::after
element, making the clearfix method unavailable. Hopefully, forcing the
creation of a block formatting context by forcing the display of kanban
records to `inline-block` should do the trick without affecting the
main layout.

addons/web/static/src/less/kanban_view.less

@@ -167,6 +167,7 @@
 
     .o_kanban_record {
         position: relative;
+        display: inline-block; // Force the creation of a block formatting context to clear float items
         min-width: 150px;
         margin: 0 @o-kanban-record-margin -1px;