Remove unnecessary pointer-events property

The inline controls use to cover the full height of the right-side
of excerpts, not just the visible area occupied by the 'More' and
'Less' links. This is no longer the case.

The use of 'pointer-events' here also caused the 'More' link
to be unresponsive in Microsoft Edge. There may be a difference
in behavior between Edge and FF/Chrome when nested elements
have different pointer-events values, but I haven't verified
this yet.

h/static/styles/excerpt.scss

@@ -22,11 +22,9 @@
     position: absolute;
     right: 0;
     bottom: 0;
-    pointer-events: none;
   }
 
   .excerpt__toggle-link {
-    pointer-events: auto;
     padding-left: 15px;
     background-image: linear-gradient(to right, transparent 0px, white 12px);
   }