Remove duplicate bib (#214)

ir_datasets/docs/bibliography.bib

@@ -454,20 +454,6 @@ @inproceedings{Hersh2005TrecGenomics
   year={2007}
 }
 
-@inproceedings{Roberts2017TrecPm,
-  title={Overview of the TREC 2017 Precision Medicine Track},
-  author={Kirk Roberts and Dina Demner-Fushman and Ellen M. Voorhees and William R. Hersh and Steven Bedrick and Alexander J. Lazar and Shubham Pant},
-  booktitle={TREC},
-  year={2017}
-}
-
-@inproceedings{Roberts2018TrecPm,
-  title={Overview of the TREC 2018 Precision Medicine Track},
-  author={Kirk Roberts and Dina Demner-Fushman and Ellen M. Voorhees and William R. Hersh and Steven Bedrick and Alexander J. Lazar},
-  booktitle={TREC},
-  year={2018}
-}
-
 @article{Craswell2020Orcas,
   title={ORCAS: 18 Million Clicked Query-Document Pairs for Analyzing Search},
   author={Craswell, Nick and Campos, Daniel and Mitra, Bhaskar and Yilmaz, Emine and Billerbeck, Bodo},
@@ -970,4 +956,4 @@ @article{Lawrie2022HC4
   series = {Lecture Notes in Computer Science},
   site = {Stavanger, Norway},
   url = {https://arxiv.org/abs/2201.09992}
-}
+}