feat(room list): remove border between each list item

Author: florianduros

res/css/views/rooms/RoomListPanel/_RoomListItemView.pcss

@@ -31,9 +31,6 @@
     .mx_RoomListItemView_content {
         height: 100%;
         flex: 1;
-        /* The border is only under the room name and the future hover menu  */
-        border-bottom: var(--cpd-border-width-0-5) solid var(--cpd-color-bg-subtle-secondary);
-        box-sizing: border-box;
         min-width: 0;
         padding-right: var(--cpd-space-5x);