Shorten Arbitrum decay duration (#381)

* Shorten Arbitrum decay to 8 seconds

* Remove cdk change

lib/handlers/hard-quote/handler.ts

@@ -235,7 +235,7 @@ function getDecayEndTime(chainId: number, startTime: number): number {
     case ChainId.MAINNET:
       return startTime + 60; // 5 blocks
     case ChainId.ARBITRUM_ONE:
-      return startTime + 16; // 16 seconds
+      return startTime + 8; // 8 seconds
     default:
       return startTime + 30; // 30 seconds
   }