Add css As per Less Devdocs

Author: speedy008

app/design/frontend/Magento/luma/Magento_Checkout/web/css/source/module/_minicart.less

@@ -129,12 +129,6 @@
 
         .block-minicart {
             .lib-css(padding, 25px @minicart__padding-horizontal);
-            &:before {
-                right:11px;
-            }
-            &:after { 
-                right: 10px; 
-            }
             .block-title {
                 display: none;
             }
@@ -422,12 +416,6 @@
         .block-minicart {
             right: -10px;
             width: 390px;
-            &:before {
-                right:17px;
-            }
-            &:after {
-                right:16px;
-            }
         }
     }
     .minilist .action.delete,