fit_gpytorch_model is not found on botorch.fit (>0.10.0)

[unkosan]

https://stackoverflow.com/questions/78758471/cannot-import-name-fit-gpytorch-model-from-botorch-fit

According to this, botorch removed fit_gpytorch_model function on v0.11.0. However RaptGen-UI uses this function on optimization.py

Please determine whether to delete gpytorch import or fix botorch to v0.10.0

[unkosan]

#95

fixed botorch to v0.10.0 as temporary treatment