Implement tensor.recip() function to calculate elementwise reciprocals

[gzsombor]

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Changes

There was no recip() method on the tensor, which is a common feature in other tensor libraries to calculate elementwise reciprocals.

Testing

Unit tests

[antimora]

Could we also please update the following documentation with the new tensor op?

1. https://github.com/burn-rs/burn/blob/main/burn-import/SUPPORTED-ONNX-OPS.md (source)
2. https://burn.dev/book/building-blocks/tensor.html (source)

[gzsombor]

Could we also please update the following documentation with the new tensor op?

1. https://github.com/burn-rs/burn/blob/main/burn-import/SUPPORTED-ONNX-OPS.md ([source](https://github.com/antimora/burn/blob/1f531422c9590da231f6f3fc00ab011fa55c21df/burn-import/SUPPORTED-ONNX-OPS.md#L137))

2. https://burn.dev/book/building-blocks/tensor.html ([source](https://github.com/antimora/burn/blob/1f531422c9590da231f6f3fc00ab011fa55c21df/burn-book/src/building-blocks/tensor.md#L63))

I updated both, I hope, this makes sense

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (e882d41) 87.34% compared to head (b55995e) 87.37%.

Files	Patch %	Lines
burn-autodiff/src/ops/tensor.rs	95.65%	1 Missing ⚠️
burn-wgpu/src/ops/float_ops.rs	91.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #953      +/-   ##
==========================================
+ Coverage   87.34%   87.37%   +0.03%     
==========================================
  Files         493      495       +2     
  Lines       50132    50269     +137     
==========================================
+ Hits        43788    43923     +135     
- Misses       6344     6346       +2     

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[antimora]

Overall looks good. One unit test is missing for autodiff.

@nathanielsimard would know more about the fusion part since it's new to me.

[nathanielsimard]

LGTM ! Thanks for the contribution :)

[antimora]

Thank you! Approved.

[gzsombor]

Welcome! And thank you for the quick reviews!