add timezone to pydata berlin conference

Author: theopinard

_data/conferences.yml

@@ -95,6 +95,7 @@
   link: https://pydata.org/berlin2025/
   cfp_link: https://cfp.pydata.org/berlin2025/cfp
   cfp: '2025-05-04 23:59:59'
+  timezone: Europe/Berlin
   place: Berlin, Germany
   start: 2025-09-01
   end: 2025-09-03
@@ -105,7 +106,6 @@
     latitude: 52.520778408127605
     longitude: 13.416401868537298
 
-
 - conference: PyCamp España
   year: 2025
   link: https://pycamp.es/