Fix/web example

[laggui]

Checklist

• Confirmed that run-checks all script has been executed.

Changes

• Fixed getrandom compilation flag for wasm examples
• Fixed wgpu import in web example
• Added permute_nchw_to_nhwc to check for input contiguity + plane op compatibility on wasm (otherwise any plane op will enable subgroups, which might not be compatible)

Testing

Tested web examples

[codecov]

Codecov Report

Attention: Patch coverage is 76.19048% with 5 lines in your changes missing coverage. Please review.

Project coverage is 82.11%. Comparing base (8a6f37c) to head (370c61f).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
.../burn-cubecl/src/kernel/conv/conv2d/layout_swap.rs	63.63%	4 Missing ⚠️
...urn-cubecl/src/kernel/conv/conv2d/implicit_gemm.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2954      +/-   ##
==========================================
- Coverage   82.11%   82.11%   -0.01%     
==========================================
  Files         867      867              
  Lines      120268   120268              
==========================================
- Hits        98763    98762       -1     
- Misses      21505    21506       +1     

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