Fix CUDA sparse_to_dense

[albertomercurio]

Checklist

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[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 1 line in your changes missing coverage. Please review.

Project coverage is 93.59%. Comparing base (504ac18) to head (74a3c3e).
Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
ext/QuantumToolboxCUDAExt.jl	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #386      +/-   ##
==========================================
+ Coverage   93.42%   93.59%   +0.16%     
==========================================
  Files          44       44              
  Lines        2829     2826       -3     
==========================================
+ Hits         2643     2645       +2     
+ Misses        186      181       -5     

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[ytdHuang]

We should also remove the following line in runtest.jl : https://github.com/qutip/QuantumToolbox.jl/blob/main/test/runtests.jl#L73

In order to test whether our setting for allowscalar(false) really works

[albertomercurio]

I see some benchmark regression on the pseudo inverse spectrum. Very strange.

[albertomercurio]

These are the benchmarks I did locally

Dev Branch

  "Correlations and Spectrum" => 2-element BenchmarkTools.BenchmarkGroup:
          tags: []
          "Spectrum" => 2-element BenchmarkTools.BenchmarkGroup:
                  tags: []
                  "Pseudo Inverse" => TrialEstimate(22.838 ms)
                  "Exponential Series" => TrialEstimate(22.863 ms)
          "FFT Correlation" => TrialEstimate(7.536 ms)

Main Branch

"Correlations and Spectrum" => 2-element BenchmarkTools.BenchmarkGroup:
          tags: []
          "Spectrum" => 2-element BenchmarkTools.BenchmarkGroup:
                  tags: []
                  "Pseudo Inverse" => TrialEstimate(21.464 ms)
                  "Exponential Series" => TrialEstimate(22.773 ms)
          "FFT Correlation" => TrialEstimate(7.542 ms)

I think that it is not related to this PR.