Add updates for Go 1.24.

This bumps the Go version required by the v5 module (which has not yet been
tagged) to the previous Go 1.23 release.

The default GODEBUG flags when building with Go 1.24 have been changed to the
1.24 default values.

README.md

@@ -74,7 +74,7 @@ https://decred.org/downloads/
 
 ### Build from source (all platforms)
 
-- **Install Go 1.22 or 1.23**
+- **Install Go 1.23 or 1.24**
 
   Installation instructions can be found here: https://golang.org/doc/install.
   Ensure Go was installed properly and is a supported version:

debug.go

@@ -2,8 +2,8 @@
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
-//go:build go1.23
+//go:build go1.24
 
-//go:debug default=go1.23
+//go:debug default=go1.24
 
 package main

go.mod

@@ -1,6 +1,6 @@
 module decred.org/dcrwallet/v5
 
-go 1.22
+go 1.23
 
 require (
 	decred.org/cspp/v2 v2.3.0