[cleanup] Replace dead example/test URL

[bashonly]

Closes #12263

Template

Before submitting a pull request make sure you have:

• At least skimmed through contributing guidelines including yt-dlp coding conventions
• Searched the bugtracker for similar pull requests

In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under Unlicense. Check those that apply and remove the others:

• I am the original author of the code in this PR, and I am willing to release it under Unlicense
• I have read the policy against AI/LLM contributions and understand I may be blocked from the repository if it is violated

What is the purpose of your pull request? Check those that apply and remove the others:

• Fix or improvement to an extractor (Make sure to add/update tests)
• Documentation fixes / cleanup