bump go.mod to go1.23 (#1342)

* bump go.mod to go1.23

* 1.23.6

go.mod

@@ -1,8 +1,8 @@
 module github.com/slackhq/nebula
 
-go 1.22.0
+go 1.23.6
 
-toolchain go1.22.2
+toolchain go1.23.7
 
 require (
 	dario.cat/mergo v1.0.1