Revert "[clang][dataflow] Show triangle in <details> element. (#67431)"

This reverts commit fb933fc.

The commit broke buildbots due to non-ASCII characters in
HTMLLogger.css.

Author: martinboehme

clang/lib/Analysis/FlowSensitive/HTMLLogger.css

@@ -123,21 +123,10 @@ code.line:has(.bb-select):before {
   font-size: x-small;
   flex-grow: 1;
 }
-.value > summary {
+.value summary {
   background-color: #ace;
   display: flex;
-  cursor: pointer;
-}
-.value > summary::before {
-  content: '►';
-  margin-right: 0.5em;
-  font-size: 0.9em;
-}
-.value[open] > summary::before {
-  content: '▼';
-}
-.value > summary > .location {
-  margin-left: auto;
+  justify-content: space-between;
 }
 .value .address {
   font-size: xx-small;

clang/lib/Analysis/FlowSensitive/HTMLLogger.html

@@ -18,7 +18,7 @@
         <template data-if="v.value_id"><span class="address">#{{v.value_id}}</span></template>
       </span>
       <template data-if="v.location">
-        <span class="location">{{v.type}} <span class="address">@{{v.location}}</span></span>
+        <span>{{v.type}} <span class="address">@{{v.location}}</span></span>
       </template>
     </summary>
     <template