Implement opset 18 #235
Description
https://github.com/onnx/onnx/blob/main/docs/Changelog.md#version-18-of-the-default-onnx-operator-set
Operators to update:
- BitwiseAnd
- BitwiseNot
- BitwiseOr
- BitwiseXor
- ReduceMax
- ReduceMean
- ReduceMin
Also:
- Update max supported opset constant