Dropdown triangle fixes (#14028)

* Dropdown triangle fixes

Fomantic's CSS assumes the dropdown triangles are fonts but we've recently
swapped them for SVG so we need to wrestle a bit with Fomantic to get it
to display properly and not cause buttons to resize.

Fixes: https://github.com/go-gitea/gitea/issues/14014

* move css and add link

web_src/less/_review.less

@@ -142,12 +142,6 @@ a.blob-excerpt:hover {
   color: #fff;
 }
 
-.btn-review > .dropdown.icon {
-  float: right;
-  height: 12px !important;
-  margin-left: .5rem;
-}
-
 @media @mediaSm {
   #review-box > .menu {
     > .ui.segment {