auth: disable sha1 by default on non-windows

auth.go

@@ -54,7 +54,7 @@ type Auth interface {
 func (conn *Conn) Auth(methods []Auth) error {
 	if methods == nil {
 		uid := strconv.Itoa(os.Geteuid())
-		methods = []Auth{AuthExternal(uid), AuthCookieSha1(uid, getHomeDir())}
+		methods = getDefaultAuthMethods(uid)
 	}
 	in := bufio.NewReader(conn.transport)
 	err := conn.transport.SendNullByte()

auth_default_other.go

@@ -0,0 +1,8 @@
+//go:build !windows
+// +build !windows
+
+package dbus
+
+func getDefaultAuthMethods(user string) []Auth {
+	return []Auth{AuthExternal(user)}
+}

auth_default_windows.go

@@ -0,0 +1,5 @@
+package dbus
+
+func getDefaultAuthMethods(user string) []Auth {
+	return []Auth{AuthCookieSha1(user, getHomeDir())}
+}