fix: allow serving size to be hyphenated (#11161)

### What
allow serving size to be hyphen ("-")


### Related issue(s) and discussion
- Fixes #10961

lib/ProductOpener/DataQualityFood.pm

@@ -1026,6 +1026,7 @@ sub check_nutrition_data ($product_ref) {
 		# catch serving_size = "serving", regardless of setting (per 100g or per serving)
 		if (    (defined $product_ref->{serving_size})
 			and ($product_ref->{serving_size} ne "")
+			and ($product_ref->{serving_size} ne "-")
 			and ($product_ref->{serving_size} !~ /\d/))
 		{
 			push @{$product_ref->{data_quality_errors_tags}}, "en:serving-size-is-missing-digits";

tests/unit/dataqualityfood.t

@@ -569,14 +569,28 @@ ProductOpener::DataQuality::check_quality($product_ref);
 check_quality_and_test_product_has_quality_tag(
 	$product_ref,
 	'en:serving-size-is-missing-digits',
-	'serving size should contains digits', 1
+	'serving size does not contain digits', 1
 );
 $product_ref = {serving_size => "120g"};
 ProductOpener::DataQuality::check_quality($product_ref);
 check_quality_and_test_product_has_quality_tag(
 	$product_ref,
 	'en:serving-size-is-missing-digits',
-	'serving size should contains digits', 0
+	'serving size contains digits', 0
+);
+$product_ref = {serving_size => ""};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag(
+	$product_ref,
+	'en:serving-size-is-missing-digits',
+	'serving size is empty', 0
+);
+$product_ref = {serving_size => "-"};
+ProductOpener::DataQuality::check_quality($product_ref);
+check_quality_and_test_product_has_quality_tag(
+	$product_ref,
+	'en:serving-size-is-missing-digits',
+	'serving size is -', 0
 );
 
 # serving size is missing