chore(go.mod/go.sum): update dependency go to v1.26.0 (#161)

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

Author: renovate[bot]

go.mod

@@ -1,6 +1,6 @@
 module github.com/sap/nginx-ingress-controller-cop
 
-go 1.25.6
+go 1.26.0
 
 require (
 	github.com/pkg/errors v0.9.1