Update go-git to v5.4.1

Signed-off-by: Hidde Beydals <hello@hidde.co>

cmd/flux/bootstrap_git.go

@@ -30,7 +30,6 @@ import (
 	"github.com/go-git/go-git/v5/plumbing/transport/ssh"
 	"github.com/manifoldco/promptui"
 	"github.com/spf13/cobra"
-	cryptossh "golang.org/x/crypto/ssh"
 	corev1 "k8s.io/api/core/v1"
 
 	"github.com/fluxcd/flux2/internal/bootstrap"
@@ -233,20 +232,7 @@ func transportForURL(u *url.URL) (transport.AuthMethod, error) {
 		}, nil
 	case "ssh":
 		if bootstrapArgs.privateKeyFile != "" {
-			// TODO(hidde): replace custom logic with https://github.com/go-git/go-git/pull/298
-			//  once made available in go-git release.
-			bytes, err := ioutil.ReadFile(bootstrapArgs.privateKeyFile)
-			if err != nil {
-				return nil, err
-			}
-			signer, err := cryptossh.ParsePrivateKey(bytes)
-			if _, ok := err.(*cryptossh.PassphraseMissingError); ok {
-				signer, err = cryptossh.ParsePrivateKeyWithPassphrase(bytes, []byte(gitArgs.password))
-			}
-			if err != nil {
-				return nil, err
-			}
-			return &ssh.PublicKeys{Signer: signer, User: u.User.Username()}, nil
+			return ssh.NewPublicKeysFromFile(u.User.Username(), bootstrapArgs.privateKeyFile, gitArgs.password)
 		}
 		return nil, nil
 	default: