[llvm] Avoid exposing password and token from git repositories (PR #105220)

[Tulio Magno Quites Machado Filho via llvm-commits]

tuliom wrote:

I updated this PR based on the feedback received on [Discourse](https://discourse.llvm.org/t/rfc-avoid-exposing-unknown-git-repositories/80962).

Title and description have been updated accordingly.

https://github.com/llvm/llvm-project/pull/105220