Disallow invalid inline style comments in stylesheets (#9099)

res/css/structures/_RightPanel.pcss

@@ -28,7 +28,7 @@ limitations under the License.
     contain: strict;
 
     .mx_RoomView_MessageList {
-        padding: 14px 18px; // top and bottom is 4px smaller to balance with the padding set above
+        padding: 14px 18px; /* top and bottom is 4px smaller to balance with the padding set above */
     }
 }
 
@@ -61,8 +61,8 @@ limitations under the License.
     &::before {
         content: '';
         position: absolute;
-        top: 4px; // center with parent of 32px
-        left: 4px; // center with parent of 32px
+        top: 4px; /* center with parent of 32px */
+        left: 4px; /* center with parent of 32px */
         height: 24px;
         width: 24px;
         background-color: $icon-button-color;