Use a different way to force line widget margins to stay inside container

Issue #5137

lib/codemirror.css

@@ -270,7 +270,7 @@ div.CodeMirror span.CodeMirror-nonmatchingbracket {color: #a22;}
 .CodeMirror-linewidget {
   position: relative;
   z-index: 2;
-  overflow: auto;
+  padding: 0.1px; /* Force widget margins to stay inside of the container */
 }
 
 .CodeMirror-widget {}