Fix missing top border on Admin Hashtags UI (#31443)

app/javascript/styles/mastodon/tables.scss

@@ -149,6 +149,14 @@ a.table-action-link {
 }
 
 .batch-table {
+  &--no-toolbar {
+    .batch-table__toolbar {
+      position: static;
+      height: 4px;
+      border-bottom: none;
+    }
+  }
+
   &__toolbar,
   &__row {
     display: flex;

app/views/admin/tags/index.html.haml

@@ -29,7 +29,8 @@
 
 %hr.spacer/
 
-.batch-table
+.batch-table.batch-table--no-toolbar
+  .batch-table__toolbar
   .batch-table__body
     - if @tags.empty?
       = nothing_here 'nothing-here--under-tabs nothing-here--no-toolbar'