all: upgrade go directive to at least 1.23.0 [generated]

By now Go 1.24.0 has been released, and Go 1.22 is no longer supported
per the Go Release Policy (https://go.dev/doc/devel/release#policy).

For golang/go#69095.

[git-generate]
(cd . && go get go@1.23.0 && go mod tidy && go fix ./... && go mod edit -toolchain=none)

Change-Id: I4dfe2096905891f3a5c7d34c2e82c6119cdd2448
Reviewed-on: https://go-review.googlesource.com/c/arch/+/649695
Auto-Submit: Gopher Robot <gobot@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
diff --git a/go.mod b/go.mod
index 355098d..b72ba1a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,5 +1,5 @@
 module golang.org/x/arch
 
-go 1.18
+go 1.23.0
 
 require rsc.io/pdf v0.1.1