fix ST tokenizer

sentence_transformers_impl.py

@@ -63,7 +63,7 @@ class Transformer(nn.Module):
         self.auto_model = AutoModel.from_pretrained(model_name_or_path, config=self.config, cache_dir=cache_dir, **model_args)
 
         self.tokenizer = AutoTokenizer.from_pretrained(
-            "bert-base-uncased",
+            "answerdotai/ModernBERT-base",
             cache_dir=cache_dir,
             **tokenizer_args,
         )