Delete Voice

Delete a voice and its associated GCS assets.

Invalidates the user_voice and user_voice_preview Redis cache entries for the affected voice after successful deletion.

Args: voice_id: UUID of the voice to delete. x_api_key: Bearer API key from the x-api-key header. token_service: Injected token validation service. _request: Raw FastAPI Request. version: API version extracted from the version request header.

Returns: None: HTTP 204 No Content on success.