chore: remove usage of ioutil (#642)

It was deprecated as of 1.17.

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.