GPU Channel Simulation: nr_dlsim/nr_ulsim Integration + CI Test This MR is a follow-up to !3886 (merged) and extends CUDA-based channel simulation support to nr_dlsim and nr_ulsim, together with the corresponding CI tests. The MR incorporates: - Cherry-picked commits e0c204f7 and 5f344876 from !3588 - Integration of new CI physim tests using GPU-accelerated channel simulation in nr_dlsim and nr_ulsim tests, see commit c727b3bb New CI job: RAN-Channel-Simulation https://jenkins-oai.eurecom.fr/job/RAN-Channel-Simulation/