Adjust emoji-mart-anchor-bar for environments that use display scaling (#7772)

app/javascript/styles/mastodon/emoji_picker.scss

@@ -62,16 +62,16 @@
   }
 
   .emoji-mart-anchor-bar {
-    bottom: 0;
+    bottom: -1px;
   }
 }
 
 .emoji-mart-anchor-bar {
   position: absolute;
-  bottom: -3px;
+  bottom: -5px;
   left: 0;
   width: 100%;
-  height: 3px;
+  height: 4px;
   background-color: $highlight-text-color;
 }