Change colorbar args

[jeanbournhonesqueMF]

Currently it is impossible to change shrink and aspect for colorbar through "legend_kwargs" in a style.

If you try it, you get the following error :

File "/home/mprl/bournhonesquej/oper/src/labo/diagnostics/brouillard/visualisation_brouillard.py", line 63, in initialisation_figure
fig_map.legend(style=self.style, location="right")
File "/home/mprl/bournhonesquej/oper/.venv/lib/python3.11/site-packages/earthkit/plots/schemas.py", line 136, in wrapper
return function(*args, **self._update_kwargs(kwargs, keys))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mprl/bournhonesquej/oper/.venv/lib/python3.11/site-packages/earthkit/plots/components/subplots.py", line 882, in legend
legend = layer.style.legend(layer, label=kwargs.pop("label", ""), **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mprl/bournhonesquej/oper/.venv/lib/python3.11/site-packages/earthkit/plots/styles/init.py", line 649, in legend
return method(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mprl/bournhonesquej/oper/.venv/lib/python3.11/site-packages/earthkit/plots/styles/init.py", line 657, in colorbar
return styles.legends.colorbar(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/mprl/bournhonesquej/oper/.venv/lib/python3.11/site-packages/earthkit/plots/styles/legends.py", line 71, in colorbar
cbar = layer.fig.colorbar(
^^^^^^^^^^^^^^^^^^^
TypeError: matplotlib.figure.FigureBase.colorbar() got multiple values for keyword argument 'shrink'

The goal is to remove shrink and aspect args to be able to change it through the legend_kwargs argument.