chore: update default network to hardhat if not specified in env (#78)

Author: jimmychu0807

apps/contracts/hardhat.config.ts

@@ -52,7 +52,7 @@ function getNetworks(): NetworksUserConfig {
 
 const hardhatConfig: HardhatUserConfig = {
     solidity: "0.8.23",
-    defaultNetwork: process.env.DEFAULT_NETWORK || "localhost",
+    defaultNetwork: process.env.DEFAULT_NETWORK || "hardhat",
     networks: {
         hardhat: {
             chainId: 1337