go bindings: allow use of the use_gpu and flash_attn options

[AnyCPU]

This pr allows use of the model options in Go bindings: use_gpu and flash_attn.

So if you are lucky man and you work on macOS (Intel) then you could write following:

	model, err := whisper.New("../../models/ggml-base.bin", whisper.WithUseGPU(false))
	if err != nil {
		slog.Error("error initializing a whisper model", "error", err)
		return
	}