docs: Add use citation from extended SPANet paper

* Add use citation from 'Extended Symmetry Preserving Attention Networks
  for LHC Analysis'.
   - c.f. https://inspirehep.net/literature/2693496

docs/bib/use_citations.bib

@@ -1,3 +1,15 @@
+% 2023-09-04
+@article{Fenton:2023ikr,
+    author = "Fenton, Michael James and Shmakov, Alexander and Okawa, Hideki and Li, Yuji and Hsiao, Ko-Yang and Hsu, Shih-Chieh and Whiteson, Daniel and Baldi, Pierre",
+    title = "{Extended Symmetry Preserving Attention Networks for LHC Analysis}",
+    eprint = "2309.01886",
+    archivePrefix = "arXiv",
+    primaryClass = "hep-ex",
+    month = "9",
+    year = "2023",
+    journal = ""
+}
+
 % 2023-08-18
 @booklet{ATLAS-CONF-2023-040,
     author = "{ATLAS Collaboration}",