Extraneous Import in Flashlight Module with implications for dependencies
**Describe the bug**

In the recently added flashlight module, https://github.com/NVIDIA/NeMo/blob/0e70135ccf24d882dcdc549321e747199a232bdf/nemo/collections/asr/modules/flashlight_decoder.py#L102 has a never-used import `from flashlight.lib.sequence.criterion import get_data_ptr_as_bytes.` This import appears to be from a different part of flashlight, not flashlight text, so it introduces a new (huge) dependency.

Edit: The sequence bindings are in https://github.com/flashlight/sequence/.