[loop-cycle-538] refactor: remove dead airllm provider from cascade router (#459) (#481)

tests/infrastructure/test_router_cascade.py

@@ -2,7 +2,7 @@
 
 import time
 from pathlib import Path
-from unittest.mock import AsyncMock, MagicMock, patch
+from unittest.mock import AsyncMock, patch
 
 import pytest
 import yaml
@@ -489,34 +489,6 @@ class TestProviderAvailabilityCheck:
 
         assert router._check_provider_available(provider) is False
 
-    def test_check_airllm_installed(self):
-        """Test AirLLM when installed."""
-        router = CascadeRouter(config_path=Path("/nonexistent"))
-
-        provider = Provider(
-            name="airllm",
-            type="airllm",
-            enabled=True,
-            priority=1,
-        )
-
-        with patch("importlib.util.find_spec", return_value=MagicMock()):
-            assert router._check_provider_available(provider) is True
-
-    def test_check_airllm_not_installed(self):
-        """Test AirLLM when not installed."""
-        router = CascadeRouter(config_path=Path("/nonexistent"))
-
-        provider = Provider(
-            name="airllm",
-            type="airllm",
-            enabled=True,
-            priority=1,
-        )
-
-        with patch("importlib.util.find_spec", return_value=None):
-            assert router._check_provider_available(provider) is False
-
 
 class TestCascadeRouterReload:
     """Test hot-reload of providers.yaml."""