Rename .onnx.data files to .onnx_data in .gitattributes

This commit renames the filter applied to .onnx.data files in the .gitattributes file.

- Old name: .onnx.data
- New name: .onnx_data

The filter settings (lfs for large file storage, diff and merge handling) remain the same.

.gitattributes

@@ -14,7 +14,7 @@
 *.npy filter=lfs diff=lfs merge=lfs -text
 *.npz filter=lfs diff=lfs merge=lfs -text
 *.onnx filter=lfs diff=lfs merge=lfs -text
-*.onnx.data filter=lfs diff=lfs merge=lfs -text
+*.onnx_data filter=lfs diff=lfs merge=lfs -text
 *.ot filter=lfs diff=lfs merge=lfs -text
 *.parquet filter=lfs diff=lfs merge=lfs -text
 *.pb filter=lfs diff=lfs merge=lfs -text