Drop stale gemini_cli expectations: PROVIDERS expectations in
test_providers_source_of_truth + test_provider_curation, the
test_list_models_gemini_cli function (deleted the whole file since it
was the only test), the test_discussion_compression_gemini_cli function,
the test_gcli_path_updates_adapter function (its setter was removed),
the ui_gemini_cli_path references in test_mma_tier_usage_reset_fix and
test_rag_integration. These are the t1.9 minor edits.
ed