go.mod: update golang.org/x dependencies

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

Change-Id: I58bd8e7171b67f75fef3896c83de938c7ed6c3c3
Reviewed-on: https://go-review.googlesource.com/c/image/+/610655
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Auto-Submit: Gopher Robot <gobot@golang.org>
Reviewed-by: Michael Pratt <mpratt@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

go.mod

diff --git a/go.mod b/go.mod
index b3c4de4..d48331e 100644
--- a/go.mod
+++ b/go.mod
@@ -2,4 +2,4 @@
 
 go 1.18
 
-require golang.org/x/text v0.17.0
+require golang.org/x/text v0.18.0

go.sum

diff --git a/go.sum b/go.sum
index 8d2179e..d4877b0 100644
--- a/go.sum
+++ b/go.sum
@@ -1,2 +1,2 @@
-golang.org/x/text v0.17.0 h1:XtiM5bkSOt+ewxlOE/aE/AKEHibwj/6gvWMl9Rsh0Qc=
-golang.org/x/text v0.17.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=
+golang.org/x/text v0.18.0 h1:XvMDiNzPAl0jr17s6W9lcaIhGUfUORdGCNsuLmPG224=
+golang.org/x/text v0.18.0/go.mod h1:BuEKDfySbSR4drPmRPG/7iBdf8hvFMuRexcpahXilzY=