[4.0] cassiopeia (#34552)

Use font-weight: 500 for table headers

Author: brianteeman

templates/cassiopeia/scss/vendor/bootstrap/_table.scss

@@ -2,6 +2,10 @@
 
 .table {
 
+  th {
+    font-weight: 500;
+  }
+
   thead th {
     white-space: nowrap;
     border-bottom-width: 1px;