Integration 2026 week 11

* !3864 remove xran_fh_tx_send_slot_BySymbol() and xran_fh_rx_read_slot_BySymbol()
* !3967 Harmonize the use of definition for number of symbols per slot
* !3971 Limit dl_DataToUL_ACK values to 15 as per standard
* !3414 Added NTN-FR2 FDD bands defined in release 18 in Ka-band range
* !3919 Reduce number of mutex locking in MAC->RLC direction
* !3923 XNAP: Add encode/decode and unit tests for Xn Setup Request/Response/Failure
* !3965 Enable BladeRF support in gNB Docker image
* !3904 add multi-ue support to vrtsim
* !3980 SDR reordering: correct warning, and USRP: return samples written
* !3834 Use flat buffer for txdataF in gNB L1
* !3981 Bugfix: make longer telnet cmdfunc names
* Reduce timing reference value for feptx_total in 40 MHz phytest