Revert "meta: reduce train spawn rate to compensate for shared train track update"

This reverts commit df5fad1a1f.

src/core/configuration/DefaultConfig.ts

@@ -271,7 +271,7 @@ export class DefaultConfig implements Config {
   trainSpawnRate(numPlayerFactories: number): number {
     // hyperbolic decay, midpoint at 10 factories
     // expected number of trains = numPlayerFactories  / trainSpawnRate(numPlayerFactories)
-    return (numPlayerFactories + 10) * 25;
+    return (numPlayerFactories + 10) * 18;
   }
   trainGold(rel: "self" | "team" | "ally" | "other"): Gold {
     const multiplier = this.goldMultiplier();