feat: Add FLOPs tracking for nemotronh

[tejasprabhune]

What does this PR do ?

This PR adds FLOPs tracking support for Nemotron-H models (e.g. Nemotron Nano V3).

Issues

List issues that this PR closes (syntax):

n/a

Usage

• You can potentially add a usage example below

# Add a code snippet demonstrating how to use this
nemotron_flops_config, nemotronh = convert_config_to_flops_config(nemotron_pretrained_config)

Before your PR is "Ready for review"

Pre checks:

• Make sure you read and followed Contributor guidelines
• Did you write any new necessary tests?
• Did you run the unit tests and functional tests locally? Visit our Testing Guide for how to run tests
• Did you add or update any necessary documentation? Visit our Document Development Guide for how to write, build and test the docs.

Additional Information

• gated_linear_unit is added to FLOPSConfig as it is needed in _mlp_layer_flops in flops_formulas.py.

[terrykong]

@guyueh1 to review

[tejasprabhune]

Hey! Just wanted to bump this if @guyueh1 you have a chance to review :)

[guyueh1]

Added "feat:" to the title to pass test

[guyueh1]

This PR doesn't consider nemotron_h MoE models which makes me concerned. Is it possible to add moe support?