WP Wham Checkout Files Upload -- restore normal file type validation

functions.php

add_filter( 'wpwham_checkout_files_upload_validate_file_type', 'wpw20250531_restore_normal_file_type_validation', 10, 3 );
function wpw20250531_restore_normal_file_type_validation( $result, $file_uploader, $file ) {
	$result = true;
	$files_accepted = get_option( 'alg_checkout_files_upload_file_accept_' . $file_uploader, '.jpg,.jpeg,.png' );
	if ( $files_accepted > '' ) {
		$files_accepted = array_map( 'trim', explode( ',', strtolower( $files_accepted ) ) );
		if ( is_array( $files_accepted ) && ! empty( $files_accepted ) ) {
			$file_type = strtolower( '.' . pathinfo( $file['name'], PATHINFO_EXTENSION ) );
			if ( ! in_array( $file_type, $files_accepted ) ) {
				$result = array(
					'code'    => 'fail_file_type',
					'message' => sprintf(
						( get_option( 'alg_checkout_files_upload_notice_wrong_file_type_' . $file_uploader ) > '' ?
							get_option( 'alg_checkout_files_upload_notice_wrong_file_type_' . $file_uploader )
							: __( 'Wrong file type: "%s"', 'checkout-files-upload-woocommerce' ) ),
						$file['name'] 
					),
				);
			}
		}
	}
	return $result;
}