Remove timm from exporters extra (#2299)

remove timm from required dependencies

Author: echarlaix

setup.py

@@ -71,21 +71,18 @@
     ],
     "exporters": [
         "onnx",
-        "timm",
         "onnxruntime",
         "protobuf>=3.20.1",
         "transformers>=4.36,<4.53.0",
     ],
     "exporters-gpu": [
         "onnx",
-        "timm",
         "onnxruntime-gpu",
         "protobuf>=3.20.1",
         "transformers>=4.36,<4.53.0",
     ],
     "exporters-tf": [
         "onnx",
-        "timm",
         "h5py",
         "tf2onnx",
         "onnxruntime",