Keep cable pick info and the prewarm flag off Cesium objects

Submarine cables wrote each pick's info both to a per-load WeakMap and to a
__gevTeleGeography expando, always together; one cablePicks store replaces
both and resolves the same objects. The voice view-target prewarm marks its
viewer in a WeakSet instead of a __gevViewTargetPrewarmInstalled property.

src/layers/submarineCables/ingestion.js

@@ -142,7 +142,6 @@ export function createIngestion({ state, parts, source }) {
 
       const cableEntities = state._cableDataSource.entities.values;
       const landingEntities = state._landingDataSource.entities.values;
-      state._pickByEntity = new WeakMap();
       state._referenceRecords = [];
       state._surfaceRecords = [];