[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:

PR is ready for review.
Workflow run when email is hidden: https://github.com/llvm/llvm-project/actions/runs/16279434976/job/45965879699
Workflow run when email is public: https://github.com/llvm/llvm-project/actions/runs/16279496749/job/45966062207

Passed on contribution history, tagging @asl @DavidSpickett @vbvictor for feedback.

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