Minor changes to meet ruff 0.15 standards and fix some preview issues

[oerc0122]

Description of work
Miscellaneous changes to meet Ruff 0.l5 specs and fix some of the issues raised by the preview=True

Fixes
N/A

To test
Tests should pass.

[MBartkowiakSTFC]

As far as I can tell, the vector shell plots (in the q vector widget) don't work in this branch. That is, I can show the vectors preview showing the shell population, but the other tab with vector distribution within the shell throws an exception:

2026-02-23 15:13:56,413 - ERROR - process[25453] - main 36 - EXCEPTION:
<class 'numpy.core._exceptions._UFuncOutputCastingError'>
Cannot cast ufunc 'divide' output from dtype('float64') to dtype('int64') with casting rule 'same_kind'
<traceback object at 0x31c6a7080>
Traceback (most recent call last):
  File "MDANSE_GUI/InputWidgets/QVectorsWidget.py", line 257, in set_shell
    self.set_upper_limit(len(vec_dict))
  File "MDANSE_GUI/InputWidgets/QVectorsWidget.py", line 237, in set_upper_limit
    self.set_shell(current_shell, update_limit=False)
  File "MDANSE_GUI/InputWidgets/QVectorsWidget.py", line 285, in set_shell
    for dataset in vector_angular_datasets(self.qvec_config, vec_key):
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "MDANSE_GUI/Tabs/Views/PlotDataView.py", line 194, in vector_angular_datasets
    return angular_datasets_from_qarray(q_array, q_weights)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "MDANSE_GUI/Tabs/Views/PlotDataView.py", line 238, in angular_datasets_from_qarray
    counts /= np.sin(mean_angles)
numpy.core._exceptions._UFuncOutputCastingError: Cannot cast ufunc 'divide' output from dtype('float64') to dtype('int64') with casting rule 'same_kind'

[MBartkowiakSTFC]

I also think that the play button in the trajectory view doesn't work after the changes.