Update BitcoinDepositor minimum deposit amount for Sepolia (#376)

BitcoinDepositor defines minimum deposit amount which relates to the
tBTC Bridge dust threshold. To simplyfy testing the deposit dust
threshold was lowered for Sepolia, we need to align the min deposit
amount in BitcoinDepositor too, as this value is enforced in deposit
form in the dApp.

solidity/deploy/14_bitcoin_depositor_update_minimum_deposit_amount copy.ts

@@ -0,0 +1,25 @@
+import type { HardhatRuntimeEnvironment } from "hardhat/types"
+import type { DeployFunction } from "hardhat-deploy/types"
+
+const func: DeployFunction = async (hre: HardhatRuntimeEnvironment) => {
+  const { getNamedAccounts, deployments } = hre
+  const { deployer } = await getNamedAccounts()
+
+  const minimumDepositAmount = 150000000000000 // 0.00015 tBTC
+
+  await deployments.execute(
+    "BitcoinDepositor",
+    { from: deployer, log: true, waitConfirmations: 1 },
+    "updateMinDepositAmount",
+    minimumDepositAmount,
+  )
+}
+
+export default func
+
+func.tags = ["BitcoinDepositorUpdateMinimumDepositAmount"]
+func.dependencies = ["BitcoinDepositor"]
+
+// Run only on Sepolia testnet.
+func.skip = async (hre: HardhatRuntimeEnvironment): Promise<boolean> =>
+  Promise.resolve(hre.network.name !== "sepolia")