Update opensearch_mappings.json

* Remove include_in_parent property from dates field in mapping

Author: ehanson8

config/opensearch_mappings.json

@@ -104,7 +104,6 @@
       },
       "dates": {
         "type": "nested",
-        "include_in_parent": "true",
         "properties": {
           "kind": {
             "type": "keyword",