Fix TypeScript definitions generation when no helpers configured

[Copilot]

Motivation/Description of the PR

When no helpers are configured, the codeceptjs def command generated invalid TypeScript definitions that broke IDE auto-completion for the I actor. The generated steps.d.ts referenced an undefined Methods interface:

// Before (broken)
declare namespace CodeceptJS {
  interface SupportObject { I: I, current: any }
  
  interface I extends WithTranslation<Methods> {}  // Methods undefined
}

// After (fixed)
declare namespace CodeceptJS {
  interface SupportObject { I: I, current: any }
  interface Methods {}  // Now defined
  interface I extends WithTranslation<Methods> {}
}

Fix: Modified lib/command/definitions.js to always generate the Methods interface, even when empty.

Applicable helpers:

• All helpers (affects type definitions generation)

Applicable plugins:

• All plugins (affects type definitions generation)

Type of change

• 🔥 Breaking changes
• 🚀 New functionality
• 🐛 Bug fix
• 🧹 Chore
• 📋 Documentation changes/updates
• ♨️ Hot fix
• 🔨 Markdown files fix - not related to source code
• 💅 Polish code

Checklist:

• Tests have been added
• Documentation has been added (Run npm run docs)
• Lint checking (Run npm run lint)
• Local tests are passed (Run npm test)

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• google.com
  • Triggering command: node /home/REDACTED/work/CodeceptJS/CodeceptJS/bin/codecept.js run --config /home/REDACTED/work/CodeceptJS/CodeceptJS/test/data/sandbox/codecept.bdd.js --grep @fail --steps (dns block)
• googlechromelabs.github.io
  • Triggering command: node install.mjs (dns block)
• https://storage.googleapis.com/chrome-for-testing-public/138.0.7204.168/linux64/chrome-linux64.zip
  • Triggering command: node install.mjs (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

• investigate and fix the issue that no auto suggested methods of I actor are shown in test file when using I actor.

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