Update pyproject.toml

[FBumann]

Trying to solve issues with nbformat when plotting with plotly in CICD

 Traceback (most recent call last):
    File "/home/runner/work/flixopt/flixopt/examples/02_Complex/complex_example_results.py", line 23, in <module>
      results['Fernwärme'].plot_node_balance()
    File "/opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/flixopt/results.py", line 416, in plot_node_balance
      return plotting.export_figure(
             ^^^^^^^^^^^^^^^^^^^^^^^
    File "/opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/flixopt/plotting.py", line 1325, in export_figure
      fig.show()
    File "/opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/plotly/basedatatypes.py", line 3436, in show
      return pio.show(self, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    File "/opt/hostedtoolcache/Python/3.12.10/x64/lib/python3.12/site-packages/plotly/io/_renderers.py", line 425, in show
      raise ValueError(
  ValueError: Mime type rendering requires nbformat>=4.2.0 but it is not installed