feat: Session-reference-aware Unified Radix Cache for agentic multi-turn workloads (#29173)

Co-authored-by: Ishan Dhanani <ishandhanani@gmail.com>
Co-authored-by: hzh0425 <hzh0425@apache.org>
Co-authored-by: ispobock <ispobaoke@gmail.com>

test/registered/unit/server_args/test_server_args.py

@@ -1274,17 +1274,6 @@ class TestPrefillOnlyDisableKvCache(unittest.TestCase):
                     self._validate_prefill_only_args(kv_cache_dtype=kv_cache_dtype)
 
 
-class TestSessionRadixCacheServerArgs(unittest.TestCase):
-    def test_requires_priority_radix_eviction_policy(self):
-        server_args = ServerArgs(
-            model_path="dummy",
-            enable_session_radix_cache=True,
-            radix_eviction_policy="lru",
-        )
-        with self.assertRaisesRegex(ValueError, "--radix-eviction-policy priority"):
-            server_args._handle_cache_compatibility()
-
-
 class TestCudaGraphConfigDataclassAccess(CustomTestCase):
     @patch(
         "sglang.srt.model_executor.runner_backend."