fix: fix transpose empty iterable with zip(*nested) in transformations

[XuehaiPan]

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You can use the syntax close #15213 if this solves the issue #15213

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[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +1.00 🎉

Comparison is base (30db8ec) 91.97% compared to head (de6b176) 92.97%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #145      +/-   ##
==========================================
+ Coverage   91.97%   92.97%   +1.00%     
==========================================
  Files          66       66              
  Lines        2564     2574      +10     
==========================================
+ Hits         2358     2393      +35     
+ Misses        206      181      -25     

Flag	Coverage Δ
unittests	92.97% <100.00%> (+1.00%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
torchopt/base.py	83.64% <ø> (-2.73%)	⬇️
torchopt/typing.py	100.00% <ø> (ø)
torchopt/utils.py	86.77% <ø> (ø)
torchopt/diff/implicit/nn/module.py	100.00% <100.00%> (+17.86%)	⬆️
torchopt/diff/zero_order/nn/module.py	100.00% <100.00%> (+8.33%)	⬆️
torchopt/transform/scale_by_adam.py	100.00% <100.00%> (ø)
torchopt/accelerated_op/__init__.py	91.67% <0.00%> (-8.33%)	⬇️
torchopt/nn/module.py	81.36% <0.00%> (+4.09%)	⬆️
... and 2 more

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[Benjamin-eecs]

Great job on the refactor, LGTM!