[Github] Add PR author name to subscription email (#68440)

Currently the email that gets sent out to people subscribing to a label
that the bot tags on the PR doesn't include any authorship information
which some people are interested in having. This patch adds an author
field to the message with the relevant information.

Author: boomanaiden154

llvm/utils/git/github-automation.py

@@ -82,6 +82,8 @@ def run(self) -> bool:
         comment = f"""
 @llvm/{team.slug}
 
+Author: {self.issue.user.name} ({self.issue.user.login})
+
 <details>
 {body}
 </details>
@@ -165,6 +167,8 @@ def run(self) -> bool:
 {self.COMMENT_TAG}
 {team_mention}
 
+Author: {self.pr.user.name} ({self.pr.user.login})
+
 <details>
 <summary>Changes</summary>