Add Linea and Plasma support

[fedgiac]

Adds support for Linea (context) and Plasma (context) chains.

Additionally, I let the script access the env WS_NO_BUFFER_UTIL. It looks like running the script crashes without access to that var so it's basically required. It's independent of the other changes in the PR. It appears to be related to ws, a transitive dependency of Ethers. I didn't investigate further since it's a minor issue.

How to test

You can run the script using the following config file and import it in the transaction builder with the relevant safe.

config.ts

import { SingleSafeConfig } from "./src/types.ts";

const owners = [
  "0x1111111111111111111111111111111111111111",
  "0x2222222222222222222222222222222222222222",
  "0x3333333333333333333333333333333333333333",
  "0x4444444444444444444444444444444444444444",
  "0x5555555555555555555555555555555555555555",
];
export const safesToUpdate: SingleSafeConfig[] = [
  {
    safe: "0x423cEc87f19F0778f549846e0801ee267a917935",
    network: "Linea",
    newThreshold: 3,
    newOwners: owners,
  }
];

Expected result