fix ernie4_5vl tokenizer unitest for network connection error (#2530)

改动原因：单测ernie4_5vl被跳过
改动范围：去除跳过功能装饰器
影响范围：对其他代码部分无影响
潜在风险：无
以上。Approve
20250902 Miao

Author: fjjF77

tests/transformers/ernie4_5vl/test_tokenizer.py

@@ -17,11 +17,12 @@
 import unittest
 
 from paddleformers.transformers import Ernie4_5_VLTokenizer
+from paddleformers.utils.download import DownloadSource
+from tests.testing_utils import set_proxy
 
 HUB_FLAG = "aistudio"
 
 
-@unittest.skip("skipping due to connection error!")
 class Ernie4_5_VL_TokenizationTest(unittest.TestCase):
     from_pretrained_id = "PaddlePaddle/ERNIE-4.5-VL-28B-A3B-Base-PT"
     tokenizer_class = Ernie4_5_VLTokenizer
@@ -41,12 +42,14 @@ def tearDown(self):
             if os.path.exists(test_dir):
                 shutil.rmtree(test_dir)
 
+    @set_proxy(DownloadSource.AISTUDIO)
     def test_slow_tokenizer_from_pretrained(self):
         tokenizer = Ernie4_5_VLTokenizer.from_pretrained(
             self.from_pretrained_id, download_hub=HUB_FLAG, trust_remote_code=True
         )
         self.assertTrue(tokenizer is not None)
 
+    @set_proxy(DownloadSource.AISTUDIO)
     def test_slow_tokenizer_save_pretrained(self):
         tokenizer = Ernie4_5_VLTokenizer.from_pretrained(
             self.from_pretrained_id, download_hub=HUB_FLAG, trust_remote_code=True
@@ -55,6 +58,7 @@ def test_slow_tokenizer_save_pretrained(self):
         tokenizer.save_pretrained("./slow_tokenizer")
         self.assertTrue(os.path.exists("./slow_tokenizer/tokenizer_config.json"))
 
+    @set_proxy(DownloadSource.AISTUDIO)
     def test_tokenize(self):
         tokenizer = Ernie4_5_VLTokenizer.from_pretrained(
             self.from_pretrained_id, download_hub=HUB_FLAG, trust_remote_code=True