[MRG] fix synapses properties rendering

[gtdang]

Changed logic in _update_cell_params_vbox to properly build the cell_parameters_key.

The problem was here:

hnn-core/hnn_core/gui/gui.py

Lines 1974 to 1975 in 7a42650

	if "Biophysics" or 'Geometry' in cell_layer:
	cell_parameters_key += f" {cell_type.split(' ')[0]}"

if "Biophysics" will always evaluate to True.

closes #911

[asoplata]

Just double-checked this, yes this solves the issue. Merging.