Fix golang lint issues

The version and rules in the testrunner image have been updated.

Resolve the new issues identified.

pkg/csrf/csrf.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2021-2022 The Tekton Authors
+Copyright 2021-2023 The Tekton Authors
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
@@ -74,7 +74,7 @@ func (cs *csrf) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	cs.h.ServeHTTP(w, r)
 }
 
-func unauthorizedHandler(w http.ResponseWriter, r *http.Request) {
+func unauthorizedHandler(w http.ResponseWriter, _ *http.Request) {
 	http.Error(w, fmt.Sprintf("%s - %s",
 		http.StatusText(http.StatusForbidden), errorNoHeader),
 		http.StatusForbidden)

pkg/endpoints/cluster.go

@@ -38,7 +38,7 @@ type Properties struct {
 // GetProperties is used to get the installed namespace for the Dashboard,
 // the version of the Tekton Dashboard, the version of Tekton Pipelines,
 // when one's in read-only mode and Tekton Triggers version (if Installed)
-func (r Resource) GetProperties(response http.ResponseWriter, request *http.Request) {
+func (r Resource) GetProperties(response http.ResponseWriter, _ *http.Request) {
 	pipelineNamespace := r.Options.GetPipelinesNamespace()
 	triggersNamespace := r.Options.GetTriggersNamespace()
 	dashboardVersion := r.GetDashboardVersion()

pkg/endpoints/health.go

@@ -1,5 +1,5 @@
 /*
-Copyright 2019-2022 The Tekton Authors
+Copyright 2019-2023 The Tekton Authors
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
@@ -18,7 +18,7 @@ import (
 )
 
 // CheckHealth responds with a status code 200 signalling that the application can receive requests
-func (r Resource) CheckHealth(response http.ResponseWriter, request *http.Request) {
+func (r Resource) CheckHealth(response http.ResponseWriter, _ *http.Request) {
 	// A method here so there's scope for doing anything fancy e.g. checking anything else
 	response.WriteHeader(http.StatusOK)
 }

pkg/router/router.go

@@ -92,7 +92,7 @@ type Server struct {
 
 type responder struct{}
 
-func (r *responder) Error(w http.ResponseWriter, req *http.Request, err error) {
+func (r *responder) Error(w http.ResponseWriter, _ *http.Request, err error) {
 	logging.Log.Errorf("Error while proxying request: %v", err)
 	http.Error(w, err.Error(), http.StatusInternalServerError)
 }
@@ -126,17 +126,13 @@ func Register(r endpoints.Resource, cfg *rest.Config) (*Server, error) {
 	logging.Log.Info("Adding Kube API")
 	apiProxyPrefix := "/api/"
 	apisProxyPrefix := "/apis/"
-	proxyHandlerAPI, err := NewProxyHandler(apiProxyPrefix, cfg, 30*time.Second)
-	if err != nil {
-		return nil, err
-	}
-	proxyHandlerAPIs, err := NewProxyHandler(apisProxyPrefix, cfg, 30*time.Second)
+	proxyHandler, err := NewProxyHandler(cfg, 30*time.Second)
 	if err != nil {
 		return nil, err
 	}
 	mux := http.NewServeMux()
-	mux.Handle(apiProxyPrefix, proxyHandlerAPI)
-	mux.Handle(apisProxyPrefix, proxyHandlerAPIs)
+	mux.Handle(apiProxyPrefix, proxyHandler)
+	mux.Handle(apisProxyPrefix, proxyHandler)
 
 	logging.Log.Info("Adding Dashboard APIs")
 	registerWeb(r, mux)
@@ -149,7 +145,7 @@ func Register(r endpoints.Resource, cfg *rest.Config) (*Server, error) {
 }
 
 // NewProxyHandler creates an API proxy handler for the cluster
-func NewProxyHandler(apiProxyPrefix string, cfg *rest.Config, keepalive time.Duration) (http.Handler, error) {
+func NewProxyHandler(cfg *rest.Config, keepalive time.Duration) (http.Handler, error) {
 	host := cfg.Host
 	if !strings.HasSuffix(host, "/") {
 		host += "/"