Renamed updater_macos -> updater_darwin and removed build flag

Author: cmaglie

updater/updater_macos.go renamed to updater/updater_darwin.go

@@ -13,8 +13,6 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
-//go:build darwin
-
 package updater
 
 func start(src string) string {