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 [email protected] && 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 <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>
Reviewed-by: Cherry Mui <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>

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