[fix]fix tests of core, samplers and tokenization etc.

tests/tool_use/test_xlam_tool_parser.py

 # SPDX-License-Identifier: Apache-2.0
 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project
 
+import os
 import json
 
 import pytest
@@ -8,9 +9,10 @@ import pytest
 from vllm.entrypoints.openai.protocol import FunctionCall, ToolCall
 from vllm.entrypoints.openai.tool_parsers import xLAMToolParser
 from vllm.transformers_utils.tokenizer import get_tokenizer
+from ..utils import models_path_prefix
 
 # Use a common model that is likely to be available
-MODEL = "Salesforce/Llama-xLAM-2-8B-fc-r"
+MODEL = os.path.join(models_path_prefix, "Salesforce/Llama-xLAM-2-8B-fc-r")
 
 
 @pytest.fixture(scope="module")