Update golang.org/x dependencies to their latest tagged versions.

Change-Id: Ib730efdee37b7e1d3657e9dc3f1f708b6052f9a5
Reviewed-on: https://go-review.googlesource.com/c/tools/+/843785
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>
Reviewed-by: Mark Freeman <mark@golang.org>