[llvm] [CI] Make email check workflow fail when author's email is private in Github UI (PR #148694)

[Udit Kumar Agarwal via llvm-commits]

uditagarwal97 wrote:

Here's an example of a PR (at llvm/llvm-project) where this workflow is passing but the PR was merged with `noreply.github.com` email: https://github.com/llvm/llvm-project/pull/148617

https://github.com/llvm/llvm-project/pull/148694