fix(lint): drop unused File import after v1.1.0 handler refactor

v1.1.0 removed the explicit `File(..., alias=speaker_wav)` parameter
from the create_speech signature in favour of reading the form
directly, which made the `File` symbol unused. CI lint caught it.

No functional change.

Author: fakehec

main_tts.py

@@ -110,7 +110,7 @@
 import numpy as np
 import redis.asyncio as aioredis
 from dotenv import load_dotenv
-from fastapi import FastAPI, File, HTTPException, Request, UploadFile
+from fastapi import FastAPI, HTTPException, Request, UploadFile
 from fastapi.responses import FileResponse, JSONResponse, Response, StreamingResponse
 from pydantic import BaseModel