Update repository field for VariO (#2377)

* Remove placeholder repository field from vario.md
* Update validate-metadata.py

---------

Co-authored-by: Charles Tapley Hoyt <cthoyt@gmail.com>

Author: deepakunni3

ontology/vario.md

@@ -29,7 +29,6 @@ publications:
   title: 'Variation ontology: annotator guide'
 - id: https://www.ncbi.nlm.nih.gov/pubmed/25616435
   title: Types and effects of protein variations
-repository: N/A
 tracker: http://variationontology.org/instructions.shtml
 activity_status: orphaned
 ---

util/validate-metadata.py

@@ -175,15 +175,15 @@ def validate_metadata(item, schema):
 
         # these cases will not cause test failure and will not be logged
         # the results are just added to the metadata grid:
-        # - orphaned ontology on contact or license check
+        # - orphaned ontology on contact or license or repository check
         # - inactive ontology
         # - obsolete ontology
         # - ontology annotated with `validate: false`
         # - ontology in legacy license exception list
         if not (
             (
                 item.get("activity_status") == "orphaned"
-                and title in ["contact", "license"]
+                and title in ["contact", "license", "repository"]
             )
             or (
                 item.get("is_obsolete") is True