build: update go.mod to use Go 1.23

This enables us to use the new language features that are a part of this
release.

Author: Roasbeef

go.mod

@@ -210,6 +210,6 @@ replace google.golang.org/protobuf => github.com/lightninglabs/protobuf-go-hex-d
 // If you change this please also update docs/INSTALL.md and GO_VERSION in
 // Makefile (then run `make lint` to see where else it needs to be updated as
 // well).
-go 1.22.6
+go 1.23.6
 
 retract v0.0.2

tools/go.mod

@@ -1,6 +1,6 @@
 module github.com/lightningnetwork/lnd/tools
 
-go 1.22.6
+go 1.23.6
 
 require (
 	github.com/btcsuite/btcd v0.23.3