doc: releases: Add entries for unicast_group_info_get

Add entries for the two new functions,
bt_bap_unicast_group_get_info and bt_cap_unicast_group_get_info.

Signed-off-by: Emil Gydesen <[email protected]>

Author: Thalley

doc/releases/release-notes-4.3.rst

@@ -104,6 +104,8 @@ New APIs and options
     * :c:func:`bt_bap_broadcast_source_foreach_stream`
     * :c:func:`bt_cap_initiator_broadcast_foreach_stream`
     * :c:struct:`bt_bap_stream` now contains an ``iso`` field as a reference to the ISO channel
+    * :c:func:`bt_bap_unicast_group_get_info`
+    * :c:func:`bt_cap_unicast_group_get_info`
 
   * Host