My wife had a business in 2023 but it has been dissolved. It no longer exists. Are there any special things I need to do when filing for 2024?

If she had employees or disposed of assets, extra steps may need to be taken.   See Closing a Business.    However, if she didn't have employees or asset sales that generated taxable gains, you can remove the business.  

If you used TurboTax last year, go to the Business/Self-Employment Income & Expenses section (Schedule C) and tell TurboTax that you stopped doing business in 2024.    Or if the business closed during 2023, you can delete the entire Schedule C.  

You can search for Schedule C and use the Jump to link to be taken to your Business Summary screen to delete or edit the business details.