MINOR: [R] Remove duplicated heading
MINOR: [R] Remove duplicated heading

Closes #13824 from thisisnic/type

Authored-by: Nic Crane <b130ca97a5c118d9797a8d384d7c894a28655aef@gmail.com>
Signed-off-by: Nic Crane <b130ca97a5c118d9797a8d384d7c894a28655aef@gmail.com>

kou/arrow,kou/arrow,kou/arrow,apache/arrow,kou/arrow,icexelloss/arrow,apache/arrow,kou/arrow,icexelloss/arrow,kou/arrow,kou/arrow,kou/arrow,apache/arrow,apache/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,apache/arrow,kou/arrow,kou/arrow,icexelloss/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,apache/arrow,apache/arrow,kou/arrow,apache/arrow,apache/arrow,kou/arrow,kou/arrow,icexelloss/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow,kou/arrow,apache/arrow,icexelloss/arrow,icexelloss/arrow