Correct former converter years

Co-authored-by: Matthew Feickert <[email protected]>

Author: graeme-a-stewart

_activities/dataanalysis.md

@@ -37,8 +37,8 @@ Contact the [convenors by email](mailto:[email protected],jamie.gooding@c
 
 ### Former Convenors
 
-- Alexander Held (ATLAS), 2023-2025
-- Nicole Skidmore (LHCb), 2021-2024
+- Alexander Held (ATLAS), 2023-2024
+- Nicole Skidmore (LHCb), 2021-2023
 - Danilo Piparo (ROOT), 2019
 - Andrea Rizzi (CMS), 2019-2020
 - Paul Laycock (Belle II), 2019-2020