Fix normalize_total for dask

[flying-sheep]

Fixes #2465

adata.var_names[~gene_subset] will throw an error if gene_subset is an 1D dask array, so we convert it to a numpy array.

[codecov]

Codecov Report

Merging #2466 (9a67bdb) into master (3e3427d) will not change coverage.
The diff coverage is 100.00%.

❗ Current head 9a67bdb differs from pull request most recent head 5bfdac5. Consider uploading reports for the commit 5bfdac5 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2466   +/-   ##
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  Coverage   71.87%   71.87%           
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  Files          98       98           
  Lines       11496    11496           
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  Hits         8263     8263           
  Misses       3233     3233           

Impacted Files	Coverage Δ
scanpy/preprocessing/_normalization.py	85.88% <100.00%> (ø)