chore: remove unused dependencies

package.json

@@ -10,7 +10,6 @@
     "@aws-sdk/client-polly": "^3.823.0",
     "@hono/node-server": "^1.14.3",
     "ffmpeg-static": "^5.2.0",
-    "fluent-ffmpeg": "^2.1.3",
     "hono": "^4.7.11",
     "openai": "^4.104.0",
     "react": "^19.1.0",