Add RubyConf Austria 2025

Author: marcoroth

_data/conferences.yml

@@ -3066,6 +3066,15 @@
   mastodon: https://ruby.social/@rockymtnruby
   announced_on: 2024-10-08
 
+- name: RubyConf Austria 2025
+  location: Austria, Europe
+  # TODO: update when dates are confirmed
+  start_date: 2025-12-31
+  end_date: 2025-12-31
+  date_precision: year
+  url: https://rubyconf.at
+  announced_on: 2025-03-12
+
 - name: RubyConf TH 2026
   location: Bangkok, Thailand
   start_date: 2026-01-31