Update Marcus Hellberg

Author: marcushellberg

java-champions.yml

@@ -1565,10 +1565,12 @@ members:
     year: 2025
     country:
       nomination: USA
-    city: San Jose
+    city: Tahoe
     social:
       twitter: https://twitter.com/marcushellberg
-      linkedin: https://www.linkedin.com/in/marcushellberg/
+      linkedin: https://www.linkedin.com/in/marcushellberg
+      bluesky: https://bsky.app/profile/marcushellberg.dev
+      github: https://github.com/marcushellberg
     avatar: img/avatars/marcushellberg.png
   - name: César Hernández
     year: 2016