WS-601: build the ingestion artifacts tar filename only once

• manifest builder's _build_artifacts_filename() is called just once, so that actual tar filename matches the one in the manifest.

apps/cli/executables/pexable/ingest_envoy/ingest_envoy/ingestion_manifest.py

@@ -203,7 +203,7 @@ class IngestionManifestBuilder:
         manifest.output_group.ancillary_products.append(artifacts_ap)
 
         manifest_file = manifest.write()
-        artifacts_file = self.staging_source_dir / self._build_artifacts_filename()
+        artifacts_file = self.staging_source_dir / artifacts_filename
         self.write_ingestion_artifacts_tar(artifacts_file)
 
         return manifest, manifest_file