Revert #13647 and #13638 (#13666)

Revert #13647 and #13638 (#13666)

#13638 and #13647 attempted to replace the generic 'dotnet-bot' e-mail
address with PR authors' e-mail addresses when uploading perf data to
BenchView. Unfortunately, these changes are still broken for some users
(specifically, if a user's e-mail address is not published/visible on
their GitHub profile).

There is no clean way to implement the proper fix, and the right fix
will change once pipeline support is available. Rather than putting in
something hacky now, I'm reverting these changes to unblock PRs. We
should revisit these changes after pipeline jobs are available.