[llvm] github-automation: Use a single comment for team mentions on pull req… (PR #66037)

[Mehdi Amini via llvm-commits]

================
@@ -83,6 +83,15 @@ def __init__(self, token: str, repo: str, pr_number: int, label_name: str):
         self.org = github.Github(token).get_organization(self.repo.organization.login)
         self.pr = self.repo.get_issue(pr_number).as_pull_request()
         self._team_name = "pr-subscribers-{}".format(label_name).lower()
+        self.COMMENT_TAG = "<!--LLVM PR SUMMARY COMMENT-->\n"
+
+    def get_summary_comment(self) -> github.IssueComment.IssueComment:
+        for comment in self.pr.as_issue().get_comments():
+            if not self.COMMENT_TAG in comment.body:
+                continue
+            return comment
----------------
joker-eph wrote:

```suggestion
            if self.COMMENT_TAG in comment.body:
                return comment
```

https://github.com/llvm/llvm-project/pull/66037