Style: Replace header guards with #pragma once

modules/zip/zip_packer.h

@@ -28,8 +28,7 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                 */
 /**************************************************************************/
 
-#ifndef ZIP_PACKER_H
-#define ZIP_PACKER_H
+#pragma once
 
 #include "core/io/file_access.h"
 #include "core/object/ref_counted.h"
@@ -64,5 +63,3 @@ public:
 };
 
 VARIANT_ENUM_CAST(ZIPPacker::ZipAppend)
-
-#endif // ZIP_PACKER_H