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

Change-Id: Id3afb41fc96c3eaa63241116bb332d4779e6b5f6
Reviewed-on: https://go-review.googlesource.com/c/net/+/694175
Reviewed-by: David Chase <[email protected]>
Auto-Submit: Gopher Robot <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>