openapi.json: Set the API version from config

We don't need to hard code this in the JSON anymore since we are
reading and modifying it now for the server config anyways.

dspace_statistics_api/app.py

@@ -58,6 +58,9 @@ class OpenAPIJSONResource:
             if DSPACE_STATISTICS_API_URL != "":
                 data["servers"] = [{"url": DSPACE_STATISTICS_API_URL}]
 
+            # Set the version in the schema so Swagger UI can display it
+            data["info"]["version"] = VERSION
+
             resp.body = json.dumps(data)