[llvm] github-automation.py: Avoid duplicate pings (PR #184321)

[Kleis Auke Wolthuizen via llvm-commits]

https://github.com/kleisauke created https://github.com/llvm/llvm-project/pull/184321

Follow-up to: #149653.

As noticed in: https://github.com/llvm/llvm-project/pull/184288#issuecomment-3988440497.

>From dd0f73123f08314f34133a24e862637930ce89bd Mon Sep 17 00:00:00 2001
From: Kleis Auke Wolthuizen <github at kleisauke.nl>
Date: Tue, 3 Mar 2026 12:10:07 +0100
Subject: [PATCH] github-automation.py: Avoid duplicate pings

Follow-up to: #149653.
---
 llvm/utils/git/github-automation.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/llvm/utils/git/github-automation.py b/llvm/utils/git/github-automation.py
index 2f4f805023bad..08990a3a9f80c 100755
--- a/llvm/utils/git/github-automation.py
+++ b/llvm/utils/git/github-automation.py
@@ -673,7 +673,8 @@ def pr_request_review(self, pr: github.PullRequest.PullRequest):
                 for review in pull.get_reviews():
                     if review.state != "APPROVED":
                         continue
-                    reviewers.append(review.user.login)
+                    if review.user.login not in reviewers:
+                        reviewers.append(review.user.login)
         if len(reviewers):
             message = "{} What do you think about merging this PR to the release branch?".format(
                 " ".join(["@" + r for r in reviewers])