fix(core): Prevent shutdown error in regular mode

[ivov]

Dynamically import WorkerServer to prevent ScalingService from being registered in the DI container when running a main in regular mode.

ComponentShutdownError: Failed to shutdown gracefully
    at ShutdownService.shutdownComponent (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:113:29)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at /Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:99:41
    at async Promise.allSettled (index 0)
    at ShutdownService.startShutdown (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:98:4)
    at ShutdownService.waitForShutdown (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:88:3)
    at /Users/ivov/Development/n8n/packages/cli/src/commands/base-command.ts:329:4 {
  level: 'error',
  tags: { packageName: 'cli' },
  extra: { component: 'ScalingService.stop()' },
  [cause]: TypeError: Cannot read properties of undefined (reading 'pause')
      at ScalingService.stop (/Users/ivov/Development/n8n/packages/cli/src/scaling/scaling.service.ts:91:20)
      at ShutdownService.shutdownComponent (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:110:17)
      at /Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:99:52
      at Array.map (<anonymous>)
      at ShutdownService.startShutdown (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:99:18)
      at ShutdownService.shutdown (/Users/ivov/Development/n8n/packages/cli/src/shutdown/shutdown.service.ts:79:31)
      at /Users/ivov/Development/n8n/packages/cli/src/commands/base-command.ts:327:25
      at ReadStream.<anonymous> (/Users/ivov/Development/n8n/packages/cli/src/commands/start.ts:335:45)
      at ReadStream.emit (node:events:519:28)
      at ReadStream.emit (node:domain:488:12)
} { component: 'ScalingService.stop()' }

[cypress]

n8n    Run #6901

Run Properties:   Passed #6901  •  b8c27cf5d2: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 ivov 🗃️ e2e/*

Project	n8n
Branch Review	prevent-shutdown-error
Run status	Passed #6901
Run duration	04m 38s
Commit	b8c27cf5d2: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 ivov 🗃️ e2e/*
Committer	Iván Ovejero
View all properties for this run ↗︎

---

Test results
Failures	0
Flaky	0
Pending	0
Skipped	0
Passing	430
View all changes introduced in this branch ↗︎

[github-actions]

✅ All Cypress E2E specs passed

[janober]

Got released with n8n@1.60.0