Update dependency go to v1.23.6 (#72)

Co-authored-by: elastic-renovate-prod[bot] <174716857+elastic-renovate-prod[bot]@users.noreply.github.com>
Co-authored-by: Daniel Mitterdorfer <danielmitterdorfer@users.noreply.github.com>

Author: elastic-renovate-prod[bot]

go.mod

@@ -2,7 +2,7 @@ module github.com/elastic/xk6-output-elasticsearch
 
 go 1.21.4
 
-toolchain go1.23.5
+toolchain go1.23.6
 
 require (
 	github.com/elastic/go-elasticsearch/v8 v8.1.0