fix malformed citation.bib file (#304)

Author: mainrs

CITATION.bib

@@ -2,7 +2,6 @@ @Conference{legat2023multivariate
   author       = {Legat, Beno{\^\i}t},
   title        = {Multivariate polynomials in {Julia}},
   month        = jul,
-  year         = 2022,
   booktitle    = {JuliaCon},
   year         = {2022},
   url          = {https://pretalx.com/juliacon-2022/talk/TRFSJY/},