Fix and remove ugly css around the conversation component (#12022)

app/javascript/styles/mastodon/components.scss

@@ -6473,8 +6473,8 @@ noscript {
       overflow: hidden;
       text-overflow: ellipsis;
       margin-bottom: 4px;
-      flex-basis: 170px;
-      flex-shrink: 1000;
+      flex-basis: 90px;
+      flex-grow: 1;
 
       a {
         color: $primary-text-color;