[llvm] Add github workflow that checks if a private email address was used to contribute to the repo and warn in this case (PR #80514)

[Anton Korobeynikov via llvm-commits]

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@@ -0,0 +1,40 @@
+name: "Check for private emails used in PRs"
+
+on: pull_request_target
+
+permissions:
+  contents: read
+
+jobs:
+  validate_email:
+    permissions:
+      pull-requests: write
+    runs-on: ubuntu-latest
+    if: github.repository == 'llvm/llvm-project'
+    steps:
+      - name: Fetch LLVM sources
+        uses: actions/checkout at v4
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
----------------
asl wrote:

Emails could come from different places, but we mostly bother about email of author in the commit (which has to set up manually from via `git config` if one uses git CLI and private email address, so must be done explicitly) and I thought this is the most bullet-proof way to do this.

https://github.com/llvm/llvm-project/pull/80514