fix(secrets): file permission value does not comply with spec

closes #10783

Compose Spec mentions that default values for secrets is `0444` aka. world-readable permissions. However, the value was previously set to `0400`. 


Signed-off-by: Shan Desai <[email protected]>

pkg/compose/secrets.go

@@ -58,7 +58,7 @@ func createTar(env string, config types.ServiceSecretConfig) (bytes.Buffer, erro
 	value := []byte(env)
 	b := bytes.Buffer{}
 	tarWriter := tar.NewWriter(&b)
-	mode := uint32(0o400)
+	mode := uint32(0o444)
 	if config.Mode != nil {
 		mode = *config.Mode
 	}