Picks up upstream MeshCore 1.17.1.
Notable upstream content:
- 1.17.1 version/build-date bump in the example MyMesh headers.
- nRF52: combine radio entropy with CC310 RNG.
- Companion FEM prefs: load/save of fem_ properties commented out until they
can be set from the client.
- Scoped reply routing: replies no longer dropped when flood.max.unscoped is
low (RoutingPolicy + unit tests).
- nRF52 unused-pin sweep (T1, T-Echo Lite, MeshPocket).
No conflicts.