Generated CSS has duplicate table style entries

[jamieburchell]

table caption + thead tr:first-child th,
table caption + thead tr:first-child td,
table caption + thead tr:first-child th, /* dupe */
table caption + thead tr:first-child td, /* dupe */
table colgroup + thead tr:first-child th,
table colgroup + thead tr:first-child td,
table colgroup + thead tr:first-child th, /* dupe */
table colgroup + thead tr:first-child td, /* dupe */
table thead:first-child tr:first-child th,
table thead:first-child tr:first-child td,
table thead:first-child tr:first-child th, /* dupe */
table thead:first-child tr:first-child td /* dupe */ {
  border-block-start: 1px solid rgba(128, 128, 128, 0.5019607843);
}