Fix threads rendering issue in Safari (#8298)

Author: t3chguy

res/css/views/right_panel/_ThreadPanel.scss

@@ -237,7 +237,7 @@ limitations under the License.
         text-align: left;
         font-size: $font-12px;
         align-items: center;
-        justify-content: end;
+        justify-content: flex-end;
         gap: 4px;
         position: relative;
         top: 2px;