refactor: Convert upgradeTo script to a hardhat task

hardhat.config.ts

@@ -23,6 +23,7 @@ const tasks = [
   "verifySpokePool",
   "evmRelayMessageWithdrawal",
   "testChainAdapter",
+  "upgradeSpokePool",
 ];
 
 // eslint-disable-next-line node/no-missing-require

tasks/upgradeSpokePool.ts

@@ -0,0 +1,29 @@
+import { task } from "hardhat/config";
+import { HardhatRuntimeEnvironment } from "hardhat/types";
+
+task("upgrade-spokepool", "Generate calldata to upgrade a SpokePool deployment")
+  .addParam("implementation", "New SpokePool implementation address")
+  .setAction(async function (args, hre: HardhatRuntimeEnvironment) {
+    const { implementation } = args;
+    if (!implementation) {
+      console.log("Usage: yarn hardhat upgrade-spokepool --implementation <implementation>");
+      return;
+    }
+
+    const { deployments, ethers } = hre;
+
+    if (ethers.utils.getAddress(implementation) !== implementation) {
+      throw new Error(`Implementation address must be checksummed (${implementation})`);
+    }
+
+    // @dev Any spoke pool's interface can be used here since they all should have the same upgradeTo function signature.
+    const { abi } = await deployments.get("Ethereum_SpokePool");
+    const spokePool = new ethers.Contract(implementation, abi);
+
+    const upgradeTo = spokePool.interface.encodeFunctionData("upgradeTo", [implementation]);
+    console.log(`upgradeTo bytes: `, upgradeTo);
+
+    console.log(
+      `Call relaySpokePoolAdminFunction() with the params [<chainId>, ${upgradeTo}] on the hub pool from the owner's account.`
+    );
+  });