fix: remove duplicate resource_metadata assignment in artifact_exporter

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: singledigit

samcli/lib/package/artifact_exporter.py

@@ -620,7 +620,6 @@ def export(self) -> Dict:
                 exporter.parent_parameter_values = self.parameter_values
                 exporter.resource_metadata = resource.get("Metadata")
                 exporter.language_extensions_enabled = self.language_extensions_enabled
-                exporter.resource_metadata = resource.get("Metadata")
                 exporter.export(full_path, resource_dict, self.template_dir)
 
         return self.template_dict