added field invocation_started_at in catalog validation

Author: Sourabhchrs93

src/vendor/dbt_artifacts_parser/parsers/catalog/catalog_v1.py

@@ -21,6 +21,7 @@ class Metadata(BaseParserModel):
     dbt_version: Optional[str] = "1.9.0b2"
     generated_at: Optional[str] = None
     invocation_id: Optional[str] = None
+    invocation_started_at: Optional[str] = None
     env: Optional[dict[str, str]] = None