feat: add arg to enable dft in liger (#3125)

* feat: add arg to enable dft in liger

* feat: add tests use_token_scaling

* fix: test

* fix: move check to args

tests/integrations/test_liger.py

@@ -75,3 +75,19 @@ class TestValidation:
         ):
             prepare_plugins(test_cfg)
             validate_config(test_cfg)
+
+    def test_use_token_scaling_require_flce(self, minimal_liger_cfg):
+        test_cfg = DictDefault(
+            {
+                "liger_fused_linear_cross_entropy": False,
+                "liger_use_token_scaling": True,
+            }
+            | minimal_liger_cfg
+        )
+
+        with pytest.raises(
+            ValueError,
+            match=r"`liger_use_token_scaling: true` requires `liger_fused_linear_cross_entropy` enabled.",
+        ):
+            prepare_plugins(test_cfg)
+            validate_config(test_cfg)