chore: remove dead code and junk files

- Delete modules/icons/Twitch.tsx (misnamed duplicate of Youtube.tsx, never imported)
- Delete modules/header/LyonJSHead.tsx (Pages Router legacy, never imported)
- Remove unused speakers export from data/lyonjs100-speakers.ts
- Delete leftover favicon_package_v0.16 (2).zip from public/

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

Author: Slashgear

data/lyonjs100-speakers.ts

@@ -113,8 +113,6 @@ Dans ce talk, nous verrons ce que sont les Islands ainsi que les composants serv
   },
 };
 
-export const speakers: Array<Speaker> = [matthieuLux, jeremiePatonnier, jonnyBurger, antoineCaron];
-
 export const program: Array<{ speaker: Speaker[]; talk?: Talk; youtubeId: string }> = [
   { speaker: [matthieuLux], youtubeId: 'xc169yA-pA8' },
   {