fix: mock transformers.onnx in bhashini to bypass IndicTrans2 load crash

bhashini.py

@@ -3,6 +3,20 @@ import os
 import gc
 import torch
 import threading
+import sys
+import types
+
+# --- CRITICAL SPRINT 18 PATCH ---
+# IndicTrans2 configuration requires `transformers.onnx`, which was removed in transformers 4.40+.
+# We mock it here to prevent 'ModuleNotFoundError' when loading the local models,
+# allowing compatibility with transformers>=4.48.0 (required by Ettin Reranker).
+if 'transformers.onnx' not in sys.modules:
+    mock_onnx = types.ModuleType('transformers.onnx')
+    class MockOnnxConfig:
+        pass
+    mock_onnx.OnnxConfig = MockOnnxConfig
+    sys.modules['transformers.onnx'] = mock_onnx
+# --------------------------------
 
 INDICTRANS_LANG_MAP = {
     "hindi": "hin_Deva",