Add option to disable external web scraping

[dtharumia]

Issue

First of all, great work with this project! We are running Aider non-interactively through a script and have enabled the setting to "always say yes to every confirmation". Similar to #1522, Aider is trying to automatically scrape URLs in its outputs. We would like to disable this feature in its entirety or potentially only allow it for certain hostnames. Could we block the cmd_web function here behind a config setting or environment variable so that we can restrict this behaviour even when not requiring confirmations?

Version and model info

No response