build(deps): pin transformers (#115)

Pinning transformers at >=4.25.1. Testing on Windows, pip install unstructured-inference ended up with transformers==4.24.x, which caused an ImportError when running a smoke test due to not having a class we import. That class didn't appear until 4.25.1.

Author: qued

requirements/base.in

@@ -3,4 +3,5 @@ python-multipart
 huggingface-hub
 opencv-python!=4.7.0.68
 onnxruntime
-transformers
+# NOTE(alan): Pinned because this is when the most recent module we import appeared
+transformers>=4.25.1