Add Sophia optimizer

[PeanutButterRat]

Is your feature request related to a problem? Please describe:
Sophia is a fairly new optimization algorithm for training language models and boasts some substantial improvements (2x speed up over Adam in wall-clock time in GPT-2 tests). Sophia seems like a nice addition to Fairseq2.

Describe the solution you would like:
It would be nice to offer Sophia as a finetuning recipe invoked with something like...

fairseq2 lm instruction_finetune --preset llama3_2_1b_instruct_sophiag

Describe the alternatives you have considered:
AdamW already exists as part of Fairseq2 as the default optimization algorithm.

Additional Context:
None