Fix CUDA DMRG

[mtfishman]

Fixes #170.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 90.31%. Comparing base (2e6a743) to head (dfa2ff5).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/dmrg.jl	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #171   +/-   ##
=======================================
  Coverage   90.31%   90.31%           
=======================================
  Files          54       54           
  Lines        3604     3604           
=======================================
  Hits         3255     3255           
  Misses        349      349           

Flag	Coverage Δ
docs	17.98% <ø> (ø)

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