chore(deps): update dependency go to v1.23.4 (#493)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/fclairamb/ftpserverlib
 
 go 1.21
 
-toolchain go1.23.2
+toolchain go1.23.4
 
 require (
 	github.com/fclairamb/go-log v0.5.0