R1:8dd57a1ed221

When fetching Git repositories, pass "--no-tags" to make explicit "Fetch Refs" operate more narrowly

Summary:
Ref T13448. The default behavior of "git fetch '+refs/heads/master:refs/heads/master'" is to follow and fetch associated tags.

We don't want this when we pass a narrow refspec because of "Fetch Refs" configuration. Tell Git that we only want the refs we explicitly passed.

Note that this doesn't prevent us from fetching tags (if the refspec specifies them), it just stops us from fetching extra…