Fix import path for upload_file_to_s3

[rromanchuk]

The latest image tag doesn't include support for arm64

So building for myself docker compose build completes, but on creation fails with ModuleNotFoundError: No module named 'src'

services:
  media_creator:
    build:
     context: .
    container_name: mcp-media-creator
    restart: always
    ports:
      - "8961:8961"
    environment:
      AWS_REGION: us-east-1
      S3_BUCKET: libre-mcp-media-creator

can be reproduced with python src/run_sse.py