[Bug]: Move BPX to an optional dependency on the PyBOP

[Dibyendu-IITKGP]

Python Version

Python 3.10.12

Describe the bug

BPX 0.4.0 requires Pydantic<2. This causes conflict when I am trying to use Battery-Data_Toolkit.

Steps to reproduce the behaviour

When an user wants to use Battery Data Toolkit (BDT) with PyBOP, using any library of BDT will throw an error. For example:

%pip install battery-data-toolkit
%pip install --upgrade pip ipywidgets -q
%pip install pybop -q
%pip install openpyxl
%pip install pandas --upgrade

from batdata.data import BatteryDataset
import plotly.graph_objects as go
import plotly.offline as pyo
import numpy as np

data_path = r"../data/cycler_data/batch_B12A_cell_2.h5" # set a suitable path for a H5 data
dataset = BatteryDataset.from_batdata_hdf(data_path)

---- This will cause an error.

Relevant log output

No response