chore: remove usage of ioutil (#642)

It was deprecated as of 1.17.

coderd/coderdtest/coderdtest.go

@@ -13,7 +13,6 @@ import (
 	"encoding/json"
 	"encoding/pem"
 	"io"
-	"io/ioutil"
 	"math/big"
 	"net"
 	"net/http"
@@ -323,7 +322,7 @@ func NewGoogleInstanceIdentity(t *testing.T, instanceID string, expired bool) (*
 			require.NoError(t, err)
 			return &http.Response{
 				StatusCode: http.StatusOK,
-				Body:       ioutil.NopCloser(bytes.NewReader(data)),
+				Body:       io.NopCloser(bytes.NewReader(data)),
 				Header:     make(http.Header),
 			}, nil
 		}),
@@ -334,7 +333,7 @@ func NewGoogleInstanceIdentity(t *testing.T, instanceID string, expired bool) (*
 		Transport: roundTripper(func(r *http.Request) (*http.Response, error) {
 			return &http.Response{
 				StatusCode: http.StatusOK,
-				Body:       ioutil.NopCloser(bytes.NewReader([]byte(signedKey))),
+				Body:       io.NopCloser(bytes.NewReader([]byte(signedKey))),
 				Header:     make(http.Header),
 			}, nil
 		}),
@@ -379,19 +378,19 @@ func NewAWSInstanceIdentity(t *testing.T, instanceID string) (awsidentity.Certif
 				case "/latest/api/token":
 					return &http.Response{
 						StatusCode: http.StatusOK,
-						Body:       ioutil.NopCloser(bytes.NewReader([]byte("faketoken"))),
+						Body:       io.NopCloser(bytes.NewReader([]byte("faketoken"))),
 						Header:     make(http.Header),
 					}, nil
 				case "/latest/dynamic/instance-identity/signature":
 					return &http.Response{
 						StatusCode: http.StatusOK,
-						Body:       ioutil.NopCloser(bytes.NewReader(signature)),
+						Body:       io.NopCloser(bytes.NewReader(signature)),
 						Header:     make(http.Header),
 					}, nil
 				case "/latest/dynamic/instance-identity/document":
 					return &http.Response{
 						StatusCode: http.StatusOK,
-						Body:       ioutil.NopCloser(bytes.NewReader(document)),
+						Body:       io.NopCloser(bytes.NewReader(document)),
 						Header:     make(http.Header),
 					}, nil
 				default:

coderd/database/dump/main.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"database/sql"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -81,7 +80,7 @@ func main() {
 	if !ok {
 		panic("couldn't get caller path")
 	}
-	err = ioutil.WriteFile(filepath.Join(mainPath, "..", "..", "dump.sql"), []byte(dump), 0600)
+	err = os.WriteFile(filepath.Join(mainPath, "..", "..", "dump.sql"), []byte(dump), 0600)
 	if err != nil {
 		panic(err)
 	}

coderd/database/postgres/postgres.go

@@ -3,7 +3,6 @@ package postgres
 import (
 	"database/sql"
 	"fmt"
-	"io/ioutil"
 	"net"
 	"os"
 	"sync"
@@ -48,10 +47,12 @@ func Open() (string, func(), error) {
 	if err != nil {
 		return "", nil, xerrors.Errorf("create pool: %w", err)
 	}
-	tempDir, err := ioutil.TempDir(os.TempDir(), "postgres")
+
+	tempDir, err := os.MkdirTemp(os.TempDir(), "postgres")
 	if err != nil {
 		return "", nil, xerrors.Errorf("create tempdir: %w", err)
 	}
+
 	openPortMutex.Lock()
 	// Pick an explicit port on the host to connect to 5432.
 	// This is necessary so we can configure the port to only use ipv4.