refactor(eleventy-config)!: migrate to eleventy v3

[arashagp]

Description

Tasks

• 📝 Self-Review: Ensure that you have thoroughly reviewed your own code changes.
• 📚 Code Documentation: Update or create all necessary documentation within the code.
• 📖 User Guides: Add necessary guides to the help document, including README or other help files (if applicable).
• 🎨 Formatting: Ensure that the code is properly formatted.
• 📅 Daily Report: Record the changes in the company's daily report, if applicable.
• 🔄 Rebase: Ensure your branch is rebased and updated based on the default branch.
• ⬆️ GitHub Project & Assignee: Ensure this pull request is correctly assigned and added to the appropriate GitHub project with the correct status.
• ✅ Local Deployment Testing (If Applicable): If the changes affect the application's functionality, deploy and test the application locally to ensure it functions as expected.