GCC 15 compatability issues with span

The current implementation of `device_span` has issues with the new implementation of span iterators in GCC 15 and libMobility cannot be compiled. Seems related to these: [link1](https://redirect.github.com/root-project/root/issues/18837), [link2](https://redirect.github.com/gcc-mirror/gcc/commit/2af87d98e66e57d51f36220de983eff44bae98c8)