Update BIS 2026 author notification deadline

Updated the author notification deadline from March 4, 2026 to March 9, 2026 based on the official conference website (https://bisconf.org/2026). All other conference information remains accurate and unchanged.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/data/conferences/bis.yml

@@ -10,7 +10,7 @@
       timezone: AoE
     - type: notification
       label: Author notification
-      date: '2026-03-04 23:59:59'
+      date: '2026-03-09 23:59:59'
       timezone: AoE
     - type: camera_ready
       label: Final paper submission