Fix a bib entry

[lgoettgens]

Building the documentation currently prints the following error:

┌ Error: Entry D-VJL24 is missing the journal field(s).
└ @ BibInternal ~/.julia/packages/BibInternal/2EG8G/src/bibtex.jl:89

This is resolved here by following the last bullet point of https://docs.oscar-system.org/dev/DeveloperDocumentation/documentation/#Updating-the-bibliography, i.e. arxiv-only references need to be of type @Misc instead of @Article.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 84.38%. Comparing base (75dd78a) to head (6c837a3).
Report is 1 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4389   +/-   ##
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  Coverage   84.38%   84.38%           
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  Files         656      656           
  Lines       87201    87201           
=======================================
  Hits        73583    73583           
  Misses      13618    13618