ROOT Patch, main branch (2023.11.29.)

Added a patch for ROOT's "WebUI vulnerability".

At the same time removed the "outdated ROOT patches" from the repository, as a simple cleanup.

Since the CI was giving me a problem with the TGZ download (a la ATLINFR-5168), I also took this opportunity to make https://cern.ch/atlas-software-dist-eos/externals/ROOT the primary pickup location of the TGZ in this same MR. 🤔