build: make go1.23 the minimum go version

This is necessary now that golang.org/x/crypto is only allowing the
last two versions of Go.

See: https://go.googlesource.com/crypto/+/89ff08d67c4d79f9ac619aaf1f7388888798651f

fs/versioncheck.go

@@ -1,7 +1,7 @@
-//go:build !go1.22
+//go:build !go1.23
 
 package fs
 
-// Upgrade to Go version 1.22 to compile rclone - latest stable go
+// Upgrade to Go version 1.23 to compile rclone - latest stable go
 // compiler recommended.
-func init() { Go_version_1_22_required_for_compilation() }
+func init() { Go_version_1_23_required_for_compilation() }