Warn when deleting symlinks that point outside temp dir

[marcphilipp]

This is a follow-up on a discussion we had about #4301.

Deliverables

• Document that symlinks in temp dirs are deleted but not their targets (if they reside outside of the temp dir)
• Log a warning for every symlink that is deleted but points to a target outside the temp dir

[YongGoose]

@marcphilipp

I understand that version 5.12.0-RC2 is scheduled for release this Friday.
Since there are no contributors, it could delay your timeline, I’d like to help resolve this issue as quickly as possible if I can. 🚀

Additionally, could you provide any additional information that might help in addressing this issue?

[marcphilipp]

Thanks for the offer! However, it's already done in my head (meaning that I "only need to write it down") and since, as you've pointed out, we don't want this to delay the release, I'll take a stab myself. I should probably have assigned myself right away.