Update _data/alumni.yml

Co-authored-by: Nathan Ryan <[email protected]>

Author: katyhuff

_data/alumni.yml

@@ -659,7 +659,7 @@
 
 - name: Nathan Ryan
   pic: /img/people/ryann.png
-  dates: 2022-2025
+  dates: 2020-2025
   role: Graduate Research Assistant
   src: https://nsryan.github.io/
   url: http://nsryan.github.io/