Maintenance: use io instead of ioutil if possible

internal/updater/providers/pia/api.go

@@ -6,7 +6,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"net/http"
 )
@@ -54,7 +54,7 @@ func fetchAPI(ctx context.Context, client *http.Client) (
 		return data, fmt.Errorf("%w: %s", ErrHTTPStatusCodeNotOK, response.Status)
 	}
 
-	b, err := ioutil.ReadAll(response.Body)
+	b, err := io.ReadAll(response.Body)
 	if err != nil {
 		return data, err
 	}

internal/updater/unzip/extract.go

@@ -3,7 +3,7 @@ package unzip
 import (
 	"archive/zip"
 	"bytes"
-	"io/ioutil"
+	"io"
 	"path/filepath"
 	"strings"
 )
@@ -24,7 +24,7 @@ func zipExtractAll(zipBytes []byte) (contents map[string][]byte, err error) {
 			return nil, err
 		}
 		defer f.Close()
-		contents[fileName], err = ioutil.ReadAll(f)
+		contents[fileName], err = io.ReadAll(f)
 		if err != nil {
 			return nil, err
 		}

internal/updater/unzip/fetch.go

@@ -4,7 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net/http"
 )
 
@@ -31,7 +31,7 @@ func (u *unzipper) FetchAndExtract(ctx context.Context, url string) (
 		return nil, fmt.Errorf("%w: %s for %s", ErrHTTPStatusCodeNotOK, response.Status, url)
 	}
 
-	b, err := ioutil.ReadAll(response.Body)
+	b, err := io.ReadAll(response.Body)
 	if err != nil {
 		return nil, err
 	}