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

Change-Id: Ide89bcc1f833bf050be936ac0493052217f4cb7a
Reviewed-on: https://go-review.googlesource.com/c/text/+/812220
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Mark Freeman <markfreeman@google.com>
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