fix(worker): get dirname by fileURLToPath

[sorich87]

@roggervalf tried to fix an issue with running sandboxed jobs in ESM environments by using module.filename (see #2296), but module.filename returns undefined and main.js path cannot be resolved.

Changing to fileURLToPath(import.meta.url) fixes the issue.

Context: We're trying to run sandboxed jobs with Next.js and getting the following error:

ENOENT: no such file or directory, stat '/xxx/nextjs/dist/cjs/classes/main.js'
    at Object.statSync (node:fs:1658:25)
    at new Worker (webpack-internal:///(instrument)/./node_modules/bullmq/dist/esm/classes/worker.js:114:53)
    at emailWorker (webpack-internal:///(instrument)/./src/jobs/email.ts:44:25)
    at Module.register (webpack-internal:///(instrument)/./src/instrumentation.ts:17:9)
    at async DevServer.runInstrumentationHookIfAvailable (/xxx/nextjs/node_modules/next/dist/server/dev/next-dev-server.js:437:17)
    at async Span.traceAsyncFn (/xxx/nextjs/node_modules/next/dist/trace/trace.js:154:20)
    at async DevServer.prepareImpl (/xxx/nextjs/node_modules/next/dist/server/dev/next-dev-server.js:214:9)
    at async NextServer.prepare (/xxx/nextjs/node_modules/next/dist/server/next.js:161:13)
    at async initializeImpl (/xxx/nextjs/node_modules/next/dist/server/lib/render-server.js:98:5)
    at async initialize (/xxx/nextjs/node_modules/next/dist/server/lib/router-server.js:423:22)
    at async Server.<anonymous> (/xxx/nextjs/node_modules/next/dist/server/lib/start-server.js:249:36) {
  errno: -2,
  code: 'ENOENT',
  syscall: 'stat',
  path: '/xxx/nextjs/dist/cjs/classes/main.js'
}

[manast]

I wonder, do you have some explanation or link on to why this change is better than the existing code?

[manast]

Wouldn't be safer the following:

const dirname = path.dirname(module.filename || fileURLToPath(import.meta.url) || __filename);

[manast]

or even:

const dirname = path.dirname(module.filename || __filename || fileURLToPath(import.meta.url) );