Merge pull request #6935 from bangerth/citing

Remove a duplicate citation.

Author: tjhei

doc/manual/citing_aspect.bib

@@ -3353,18 +3353,6 @@ @article{Li2026
   url = {http://doi.org/10.1016/j.epsl.2026.119878},
 }
 
-
-@article{Neuharth2026,
-  author = { Neuharth, Derek and Behr, Whitney M. and Holt, Adam F. },
-  title = { The role of along-strike variations in interface rheology on subduction dynamics: constraints from three-dimensional numerical models },
-  year = { 2026 },
-  volume = { 244 },
-  issue = { 3 },
-  pages = { 105 },
-  doi = {10.1093/gji/ggaf515},
-  url = {http://doi.org/10.1093/gji/ggaf515},
-}
-
 @Article{Lin2026,
 author={Lin, Jian
 and Lin, Wule