As per 3GPP TS 48.008 §3.2.1.25, HANDOVER PERFORMED must report the target cell. Add an optional cell_id parameter to the template (defaulting to '?' for backward compatibility) and update the two intra-BSC handover test helpers to assert that the Cell Identifier IE carries the target BTS (BTS 1: MCC=001 MNC=01 LAC=1 CI=1).
Also remove the unnecessary interleave wrapper in f_tc_ho_during_lcs_loc_req(): the two receives arrive on separate ports (RAN_CONN vs BSSAP_LE) so sequential receive is sufficient.
