determining chainid inside of deploy script

[makinghappen]

this.__hardhatContext.environment.network does not contain chainId property, this property is available for other L1 networks on hardhat and it is convenient to use it to determine chain id for saving contract addresses.

{
  name: 'zkSyncTestnet',
  config: {
    accounts: {
      initialIndex: 0,
      count: 20,
      path: "m/44'/60'/0'/0",
      passphrase: '',
      mnemonic: ''
    },
    gas: 'auto',
    gasPrice: 'auto',
    gasMultiplier: 1,
    httpHeaders: {},
    timeout: 20000,
    url: 'https://zksync2-testnet.zksync.dev',
    ethNetwork: 'goerli',
    zksync: true
  },
}