_content/blog: fix date on tutorials-go.18.md

Change-Id: Ie926a25fb0d239e716288c647ddb78f771b074f5
Reviewed-on: https://go-review.googlesource.com/c/website/+/378595
Run-TryBot: Katie Hockman <katie@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
Trust: DO NOT USE <katiehockman@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

_content/blog/tutorials-go1.18.md

@@ -1,6 +1,6 @@
 ---
 title: "Two New Tutorials for 1.18"
-date: 2021-01-14
+date: 2022-01-14
 by:
 - Katie Hockman, for the Go team
 summary: Two new tutorials have been published in preparation for the release of Go 1.18.