[llvm] [clang-tools-extra] [clang] Hashpin sensitive dependencies and configure dependabot to update them automatically (PR #75859)

[Diogo Teles Sant'Anna via cfe-commits]

diogoteles08 wrote:

> He's not part of the LLVM organization and thus doesn't have write access to the monorepo, so someone else will have to merge it.

That's right, I can't merge it ☹️ 
I just updated the branch to be up to date with last main changes. @tru, can you merge it?

https://github.com/llvm/llvm-project/pull/75859