fix: remove matrix_config from fallback create_liveboard_from_model call

Function signature doesn't accept matrix_config — caused fallback to crash
with unexpected keyword argument error.

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

thoughtspot_deployer.py

@@ -2442,7 +2442,6 @@ class ThoughtSpotDeployer:
                                             num_visualizations=10,
                                             liveboard_name=liveboard_name,
                                             llm_model=llm_model,
-                                            matrix_config=matrix_config,
                                             model_columns=model_columns,
                                             prompt_logger=self.prompt_logger
                                         )