update golangci-lint action to v3, golangci-lint to v1.48.0 (#3499)

* run gofmt -s -w

* stop using the deprecated io/ioutil package

* update golangci-lint action to v3, golangci-lint to v1.48.0

internal/flowcontrol/base_flow_controller_test.go

@@ -13,6 +13,7 @@ import (
 )
 
 // on the CIs, the timing is a lot less precise, so scale every duration by this factor
+//
 //nolint:unparam
 func scaleDuration(t time.Duration) time.Duration {
 	scaleFactor := 1

internal/testdata/cert.go

@@ -3,7 +3,7 @@ package testdata
 import (
 	"crypto/tls"
 	"crypto/x509"
-	"io/ioutil"
+	"os"
 	"path"
 	"runtime"
 )
@@ -38,7 +38,7 @@ func GetTLSConfig() *tls.Config {
 // AddRootCA adds the root CA certificate to a cert pool
 func AddRootCA(certPool *x509.CertPool) {
 	caCertPath := path.Join(certPath, "ca.pem")
-	caCertRaw, err := ioutil.ReadFile(caCertPath)
+	caCertRaw, err := os.ReadFile(caCertPath)
 	if err != nil {
 		panic(err)
 	}

internal/testdata/cert_test.go

@@ -2,7 +2,7 @@ package testdata
 
 import (
 	"crypto/tls"
-	"io/ioutil"
+	"io"
 
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
@@ -24,7 +24,7 @@ var _ = Describe("certificates", func() {
 
 		conn, err := tls.Dial("tcp", "localhost:4433", &tls.Config{RootCAs: GetRootCA()})
 		Expect(err).ToNot(HaveOccurred())
-		data, err := ioutil.ReadAll(conn)
+		data, err := io.ReadAll(conn)
 		Expect(err).ToNot(HaveOccurred())
 		Expect(string(data)).To(Equal("foobar"))
 	})